1 /*
2 * Copyright (C) 2022 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/file.h>
18 #include <android-base/macros.h>
19 #include <android-base/result-gmock.h>
20 #include <gmock/gmock.h>
21 #include <gtest/gtest.h>
22 #include <stdlib.h>
23 #include <unistd.h>
24
25 #include "BpfSyscallWrappers.h"
26 #include "bpf/BpfRingbuf.h"
27 #include "bpf/BpfUtils.h"
28 #include "bpf/KernelUtils.h"
29
30 #define TEST_RINGBUF_MAGIC_NUM 12345
31
32 namespace android {
33 namespace bpf {
34 using ::android::base::testing::HasError;
35 using ::android::base::testing::HasValue;
36 using ::android::base::testing::WithCode;
37 using ::testing::AllOf;
38 using ::testing::Gt;
39 using ::testing::HasSubstr;
40 using ::testing::Lt;
41
42 class BpfRingbufTest : public ::testing::Test {
43 protected:
BpfRingbufTest()44 BpfRingbufTest()
45 : mProgPath("/sys/fs/bpf/prog_bpfRingbufProg_skfilter_ringbuf_test"),
46 mRingbufPath("/sys/fs/bpf/map_bpfRingbufProg_test_ringbuf") {}
47
SetUp()48 void SetUp() {
49 if (!android::bpf::isAtLeastKernelVersion(5, 8, 0)) {
50 GTEST_SKIP() << "BPF ring buffers not supported below 5.8";
51 }
52
53 errno = 0;
54 mProgram.reset(retrieveProgram(mProgPath.c_str()));
55 EXPECT_EQ(errno, 0);
56 ASSERT_GE(mProgram.get(), 0)
57 << mProgPath << " was either not found or inaccessible.";
58 }
59
RunProgram()60 void RunProgram() {
61 char fake_skb[128] = {};
62 EXPECT_EQ(runProgram(mProgram, fake_skb, sizeof(fake_skb)), 0);
63 }
64
RunTestN(int n)65 void RunTestN(int n) {
66 int run_count = 0;
67 uint64_t output = 0;
68 auto callback = [&](const uint64_t& value) {
69 output = value;
70 run_count++;
71 };
72
73 auto result = BpfRingbuf<uint64_t>::Create(mRingbufPath.c_str());
74 ASSERT_RESULT_OK(result);
75 EXPECT_TRUE(result.value()->isEmpty());
76
77 struct timespec t1, t2;
78 EXPECT_EQ(0, clock_gettime(CLOCK_MONOTONIC, &t1));
79 EXPECT_FALSE(result.value()->wait(1000 /*ms*/)); // false because wait should timeout
80 EXPECT_EQ(0, clock_gettime(CLOCK_MONOTONIC, &t2));
81 long long time1 = t1.tv_sec * 1000000000LL + t1.tv_nsec;
82 long long time2 = t2.tv_sec * 1000000000LL + t2.tv_nsec;
83 EXPECT_GE(time2 - time1, 1000000000 /*ns*/); // 1000 ms as ns
84
85 for (int i = 0; i < n; i++) {
86 RunProgram();
87 }
88
89 EXPECT_FALSE(result.value()->isEmpty());
90
91 EXPECT_EQ(0, clock_gettime(CLOCK_MONOTONIC, &t1));
92 EXPECT_TRUE(result.value()->wait());
93 EXPECT_EQ(0, clock_gettime(CLOCK_MONOTONIC, &t2));
94 time1 = t1.tv_sec * 1000000000LL + t1.tv_nsec;
95 time2 = t2.tv_sec * 1000000000LL + t2.tv_nsec;
96 EXPECT_LE(time2 - time1, 1000000 /*ns*/); // in x86 CF testing < 5000 ns
97
98 EXPECT_THAT(result.value()->ConsumeAll(callback), HasValue(n));
99 EXPECT_TRUE(result.value()->isEmpty());
100 EXPECT_EQ(output, TEST_RINGBUF_MAGIC_NUM);
101 EXPECT_EQ(run_count, n);
102 }
103
104 std::string mProgPath;
105 std::string mRingbufPath;
106 android::base::unique_fd mProgram;
107 };
108
TEST_F(BpfRingbufTest,ConsumeSingle)109 TEST_F(BpfRingbufTest, ConsumeSingle) { RunTestN(1); }
TEST_F(BpfRingbufTest,ConsumeMultiple)110 TEST_F(BpfRingbufTest, ConsumeMultiple) { RunTestN(3); }
111
TEST_F(BpfRingbufTest,FillAndWrap)112 TEST_F(BpfRingbufTest, FillAndWrap) {
113 int run_count = 0;
114 auto callback = [&](const uint64_t&) { run_count++; };
115
116 auto result = BpfRingbuf<uint64_t>::Create(mRingbufPath.c_str());
117 ASSERT_RESULT_OK(result);
118
119 // 4kb buffer with 16 byte payloads (8 byte data, 8 byte header) should fill
120 // after 255 iterations. Exceed that so that some events are dropped.
121 constexpr int iterations = 300;
122 for (int i = 0; i < iterations; i++) {
123 RunProgram();
124 }
125
126 // Some events were dropped, but consume all that succeeded.
127 EXPECT_THAT(result.value()->ConsumeAll(callback),
128 HasValue(AllOf(Gt(250), Lt(260))));
129 EXPECT_THAT(run_count, AllOf(Gt(250), Lt(260)));
130
131 // After consuming everything, we should be able to use the ring buffer again.
132 run_count = 0;
133 RunProgram();
134 EXPECT_THAT(result.value()->ConsumeAll(callback), HasValue(1));
135 EXPECT_EQ(run_count, 1);
136 }
137
TEST_F(BpfRingbufTest,WrongTypeSize)138 TEST_F(BpfRingbufTest, WrongTypeSize) {
139 // The program under test writes 8-byte uint64_t values so a ringbuffer for
140 // 1-byte uint8_t values will fail to read from it. Note that the map_def does
141 // not specify the value size, so we fail on read, not creation.
142 auto result = BpfRingbuf<uint8_t>::Create(mRingbufPath.c_str());
143 ASSERT_RESULT_OK(result);
144
145 RunProgram();
146
147 EXPECT_THAT(result.value()->ConsumeAll([](const uint8_t&) {}),
148 HasError(WithCode(EMSGSIZE)));
149 }
150
TEST_F(BpfRingbufTest,InvalidPath)151 TEST_F(BpfRingbufTest, InvalidPath) {
152 EXPECT_THAT(BpfRingbuf<int>::Create("/sys/fs/bpf/bad_path"),
153 HasError(WithCode(ENOENT)));
154 }
155
156 } // namespace bpf
157 } // namespace android
158