Use c program as the eBPF kernel program
With proper Clang and LLVM support. The eBPF program can be compiled and
generated from simplified C program. The original c program is
bpf_ingress.c and bpf_egress.c and the corresponding .o file the output
containing the BPF bytecode that need to be loaded into the kernel at
runtime.
Bug: 30950746
Test: run cts -m CtsNetTestCases -t android.net.cts.TrafficStatsTest
Change-Id: Iedff82bf759c979bbe8e698570eabba436b56d80
diff --git a/bpfloader/bpf_kern.h b/bpfloader/bpf_kern.h
new file mode 100644
index 0000000..ee818f8
--- /dev/null
+++ b/bpfloader/bpf_kern.h
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <linux/bpf.h>
+#include <stdint.h>
+
+#define ELF_SEC(NAME) __attribute__((section(NAME), used))
+
+struct uid_tag {
+ uint32_t uid;
+ uint32_t tag;
+};
+
+struct stats_key {
+ uint32_t uid;
+ uint32_t tag;
+ uint32_t counterSet;
+ uint32_t ifaceIndex;
+};
+
+struct stats_value {
+ uint64_t rxPackets;
+ uint64_t rxBytes;
+ uint64_t txPackets;
+ uint64_t txBytes;
+};
+
+/* helper functions called from eBPF programs written in C */
+static void* (*find_map_entry)(uint64_t map, void* key) = (void*)BPF_FUNC_map_lookup_elem;
+static int (*write_to_map_entry)(uint64_t map, void* key, void* value,
+ uint64_t flags) = (void*)BPF_FUNC_map_update_elem;
+static int (*delete_map_entry)(uint64_t map, void* key) = (void*)BPF_FUNC_map_delete_elem;
+static uint64_t (*get_socket_cookie)(struct __sk_buff* skb) = (void*)BPF_FUNC_get_socket_cookie;
+static uint32_t (*get_socket_uid)(struct __sk_buff* skb) = (void*)BPF_FUNC_get_socket_uid;
+static int (*bpf_skb_load_bytes)(struct __sk_buff* skb, int off, void* to,
+ int len) = (void*)BPF_FUNC_skb_load_bytes;
+
+#define BPF_PASS 1
+#define BPF_DROP 0