1 /*
2  * Copyright (C) 2018 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include <android-base/macros.h>
18 #include <gtest/gtest.h>
19 #include <stdlib.h>
20 #include <unistd.h>
21 #include <iostream>
22 #include "include/bpf/BpfMap.h"
23 #include "include/bpf/BpfUtils.h"
24 #include "include/libbpf_android.h"
25 
26 using ::testing::Test;
27 
28 constexpr const char tp_prog_path[] =
29         "/sys/fs/bpf/prog_bpf_load_tp_prog_tracepoint_sched_sched_switch";
30 constexpr const char tp_map_path[] = "/sys/fs/bpf/map_bpf_load_tp_prog_cpu_pid";
31 
32 namespace android {
33 namespace bpf {
34 
35 class BpfLoadTest : public testing::Test {
36   protected:
37     BpfLoadTest() {}
38     int mProgFd, mMapFd;
39 
40     void SetUp() {
41         SKIP_IF_BPF_NOT_SUPPORTED;
42 
43         unlink(tp_prog_path);
44         unlink(tp_map_path);
45 
46         EXPECT_EQ(android::bpf::loadProg("/system/etc/bpf/bpf_load_tp_prog.o"), 0);
47 
48         mProgFd = bpf_obj_get(tp_prog_path);
49         EXPECT_GT(mProgFd, 0);
50 
51         mMapFd = bpf_obj_get(tp_map_path);
52         EXPECT_GT(mMapFd, 0);
53 
54         int ret = bpf_attach_tracepoint(mProgFd, "sched", "sched_switch");
55         EXPECT_NE(ret, 0);
56     }
57 
58     void TearDown() {
59         SKIP_IF_BPF_NOT_SUPPORTED;
60 
61         close(mProgFd);
62         close(mMapFd);
63         unlink(tp_prog_path);
64         unlink(tp_map_path);
65     }
66 
67     void checkMapNonZero() {
68         // The test program installs a tracepoint on sched:sched_switch
69         // and expects the kernel to populate a PID corresponding to CPU
70         android::bpf::BpfMap<uint32_t, uint32_t> m(mMapFd);
71 
72         // Wait for program to run a little
73         sleep(1);
74 
75         int non_zero = 0;
76         const auto iterFunc = [&non_zero](const uint32_t& key, const uint32_t& val,
77                                           BpfMap<uint32_t, uint32_t>& map) {
78             if (val && !non_zero) {
79                 non_zero = 1;
80             }
81 
82             UNUSED(key);
83             UNUSED(map);
84             return android::netdutils::status::ok;
85         };
86 
87         EXPECT_OK(m.iterateWithValue(iterFunc));
88         EXPECT_EQ(non_zero, 1);
89     }
90 };
91 
92 TEST_F(BpfLoadTest, bpfCheckMap) {
93     SKIP_IF_BPF_NOT_SUPPORTED;
94 
95     checkMapNonZero();
96 }
97 
98 }  // namespace bpf
99 }  // namespace android
100