netd: Use common BPF helper for C program

The BPF helper is moved into system/bpf/include/ and is available
to all BPF programs in the include search path. Make use of it.

Only minor refactor, no functional change.

Bug: 122665156
Change-Id: Ib5b495aff83874d39abe3640fb369b2ff92b3239
Signed-off-by: Joel Fernandes <joelaf@google.com>
diff --git a/progs/netd.c b/progs/netd.c
index 73e7d28..1d47c73 100644
--- a/progs/netd.c
+++ b/progs/netd.c
@@ -43,17 +43,17 @@
 
 SEC("skfilter/whitelist/xtbpf")
 int xt_bpf_whitelist_prog(struct __sk_buff* skb) {
-    uint32_t sock_uid = get_socket_uid(skb);
+    uint32_t sock_uid = bpf_get_socket_uid(skb);
     if (is_system_uid(sock_uid)) return BPF_MATCH;
-    uint8_t* whitelistMatch = find_map_entry(&uid_owner_map, &sock_uid);
+    uint8_t* whitelistMatch = bpf_map_lookup_elem(&uid_owner_map, &sock_uid);
     if (whitelistMatch) return *whitelistMatch & HAPPY_BOX_MATCH;
     return BPF_NOMATCH;
 }
 
 SEC("skfilter/blacklist/xtbpf")
 int xt_bpf_blacklist_prog(struct __sk_buff* skb) {
-    uint32_t sock_uid = get_socket_uid(skb);
-    uint8_t* blacklistMatch = find_map_entry(&uid_owner_map, &sock_uid);
+    uint32_t sock_uid = bpf_get_socket_uid(skb);
+    uint8_t* blacklistMatch = bpf_map_lookup_elem(&uid_owner_map, &sock_uid);
     if (blacklistMatch) return *blacklistMatch & PENALTY_BOX_MATCH;
     return BPF_NOMATCH;
 }
@@ -75,7 +75,7 @@
      * run time. See UserHandle#isSameApp for detail.
      */
     uint32_t appId = (gid_uid & 0xffffffff) % PER_USER_RANGE;
-    uint8_t* internetPermission = find_map_entry(&uid_permission_map, &appId);
+    uint8_t* internetPermission = bpf_map_lookup_elem(&uid_permission_map, &appId);
     if (internetPermission) return *internetPermission & ALLOW_SOCK_CREATE;
     return NO_PERMISSION;
 }