1 /*
2 * Copyright 2021 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 * BpfHandlerTest.cpp - unit tests for BpfHandler.cpp
17 */
18
19 #include <private/android_filesystem_config.h>
20 #include <sys/socket.h>
21
22 #include <gtest/gtest.h>
23
24 #define BPF_MAP_MAKE_VISIBLE_FOR_TESTING
25 #include "BpfHandler.h"
26
27 using namespace android::bpf; // NOLINT(google-build-using-namespace): exempted
28
29 namespace android {
30 namespace net {
31
32 using base::Result;
33
34 constexpr int TEST_MAP_SIZE = 10;
35 constexpr int TEST_COOKIE = 1;
36 constexpr uid_t TEST_UID = 10086;
37 constexpr uid_t TEST_UID2 = 54321;
38 constexpr uint32_t TEST_TAG = 42;
39 constexpr uint32_t TEST_COUNTERSET = 1;
40 constexpr uint32_t TEST_PER_UID_STATS_ENTRIES_LIMIT = 3;
41 constexpr uint32_t TEST_TOTAL_UID_STATS_ENTRIES_LIMIT = 7;
42
43 #define ASSERT_VALID(x) ASSERT_TRUE((x).isValid())
44
45 class BpfHandlerTest : public ::testing::Test {
46 protected:
BpfHandlerTest()47 BpfHandlerTest()
48 : mBh(TEST_PER_UID_STATS_ENTRIES_LIMIT, TEST_TOTAL_UID_STATS_ENTRIES_LIMIT) {}
49 BpfHandler mBh;
50 BpfMap<uint64_t, UidTagValue> mFakeCookieTagMap;
51 BpfMap<StatsKey, StatsValue> mFakeStatsMapA;
52 BpfMap<uint32_t, uint32_t> mFakeConfigurationMap;
53 BpfMap<uint32_t, uint8_t> mFakeUidPermissionMap;
54
SetUp()55 void SetUp() {
56 ASSERT_EQ(0, setrlimitForTest());
57
58 mFakeCookieTagMap.resetMap(BPF_MAP_TYPE_HASH, TEST_MAP_SIZE);
59 ASSERT_VALID(mFakeCookieTagMap);
60
61 mFakeStatsMapA.resetMap(BPF_MAP_TYPE_HASH, TEST_MAP_SIZE);
62 ASSERT_VALID(mFakeStatsMapA);
63
64 mFakeConfigurationMap.resetMap(BPF_MAP_TYPE_ARRAY, CONFIGURATION_MAP_SIZE);
65 ASSERT_VALID(mFakeConfigurationMap);
66
67 mFakeUidPermissionMap.resetMap(BPF_MAP_TYPE_HASH, TEST_MAP_SIZE);
68 ASSERT_VALID(mFakeUidPermissionMap);
69
70 mBh.mCookieTagMap = mFakeCookieTagMap;
71 ASSERT_VALID(mBh.mCookieTagMap);
72 mBh.mStatsMapA = mFakeStatsMapA;
73 ASSERT_VALID(mBh.mStatsMapA);
74 mBh.mConfigurationMap = mFakeConfigurationMap;
75 ASSERT_VALID(mBh.mConfigurationMap);
76 // Always write to stats map A by default.
77 static_assert(SELECT_MAP_A == 0, "bpf map arrays are zero-initialized");
78
79 mBh.mUidPermissionMap = mFakeUidPermissionMap;
80 ASSERT_VALID(mBh.mUidPermissionMap);
81 }
82
setUpSocketAndTag(int protocol,uint64_t * cookie,uint32_t tag,uid_t uid,uid_t realUid)83 int setUpSocketAndTag(int protocol, uint64_t* cookie, uint32_t tag, uid_t uid,
84 uid_t realUid) {
85 int sock = socket(protocol, SOCK_STREAM | SOCK_CLOEXEC, 0);
86 EXPECT_LE(0, sock);
87 *cookie = getSocketCookie(sock);
88 EXPECT_NE(NONEXISTENT_COOKIE, *cookie);
89 EXPECT_EQ(0, mBh.tagSocket(sock, tag, uid, realUid));
90 return sock;
91 }
92
expectUidTag(uint64_t cookie,uid_t uid,uint32_t tag)93 void expectUidTag(uint64_t cookie, uid_t uid, uint32_t tag) {
94 Result<UidTagValue> tagResult = mFakeCookieTagMap.readValue(cookie);
95 ASSERT_RESULT_OK(tagResult);
96 EXPECT_EQ(uid, tagResult.value().uid);
97 EXPECT_EQ(tag, tagResult.value().tag);
98 }
99
expectNoTag(uint64_t cookie)100 void expectNoTag(uint64_t cookie) { EXPECT_FALSE(mFakeCookieTagMap.readValue(cookie).ok()); }
101
populateFakeStats(uint64_t cookie,uint32_t uid,uint32_t tag,StatsKey * key)102 void populateFakeStats(uint64_t cookie, uint32_t uid, uint32_t tag, StatsKey* key) {
103 UidTagValue cookieMapkey = {.uid = (uint32_t)uid, .tag = tag};
104 EXPECT_RESULT_OK(mFakeCookieTagMap.writeValue(cookie, cookieMapkey, BPF_ANY));
105 *key = {.uid = uid, .tag = tag, .counterSet = TEST_COUNTERSET, .ifaceIndex = 1};
106 StatsValue statsMapValue = {.rxPackets = 1, .rxBytes = 100};
107 EXPECT_RESULT_OK(mFakeStatsMapA.writeValue(*key, statsMapValue, BPF_ANY));
108 key->tag = 0;
109 EXPECT_RESULT_OK(mFakeStatsMapA.writeValue(*key, statsMapValue, BPF_ANY));
110 // put tag information back to statsKey
111 key->tag = tag;
112 }
113
114 template <class Key, class Value>
expectMapEmpty(BpfMap<Key,Value> & map)115 void expectMapEmpty(BpfMap<Key, Value>& map) {
116 auto isEmpty = map.isEmpty();
117 EXPECT_RESULT_OK(isEmpty);
118 EXPECT_TRUE(isEmpty.value());
119 }
120
expectTagSocketReachLimit(uint32_t tag,uint32_t uid)121 void expectTagSocketReachLimit(uint32_t tag, uint32_t uid) {
122 int sock = socket(AF_INET6, SOCK_STREAM | SOCK_CLOEXEC, 0);
123 EXPECT_LE(0, sock);
124 if (sock < 0) return;
125 uint64_t sockCookie = getSocketCookie(sock);
126 EXPECT_NE(NONEXISTENT_COOKIE, sockCookie);
127 EXPECT_EQ(-EMFILE, mBh.tagSocket(sock, tag, uid, uid));
128 expectNoTag(sockCookie);
129
130 // Delete stats entries then tag socket success
131 StatsKey key = {.uid = uid, .tag = 0, .counterSet = TEST_COUNTERSET, .ifaceIndex = 1};
132 ASSERT_RESULT_OK(mFakeStatsMapA.deleteValue(key));
133 EXPECT_EQ(0, mBh.tagSocket(sock, tag, uid, uid));
134 expectUidTag(sockCookie, uid, tag);
135 }
136 };
137
TEST_F(BpfHandlerTest,TestTagSocketV4)138 TEST_F(BpfHandlerTest, TestTagSocketV4) {
139 uint64_t sockCookie;
140 int v4socket = setUpSocketAndTag(AF_INET, &sockCookie, TEST_TAG, TEST_UID, TEST_UID);
141 expectUidTag(sockCookie, TEST_UID, TEST_TAG);
142 ASSERT_EQ(0, mBh.untagSocket(v4socket));
143 expectNoTag(sockCookie);
144 expectMapEmpty(mFakeCookieTagMap);
145 }
146
TEST_F(BpfHandlerTest,TestReTagSocket)147 TEST_F(BpfHandlerTest, TestReTagSocket) {
148 uint64_t sockCookie;
149 int v4socket = setUpSocketAndTag(AF_INET, &sockCookie, TEST_TAG, TEST_UID, TEST_UID);
150 expectUidTag(sockCookie, TEST_UID, TEST_TAG);
151 ASSERT_EQ(0, mBh.tagSocket(v4socket, TEST_TAG + 1, TEST_UID + 1, TEST_UID + 1));
152 expectUidTag(sockCookie, TEST_UID + 1, TEST_TAG + 1);
153 }
154
TEST_F(BpfHandlerTest,TestTagTwoSockets)155 TEST_F(BpfHandlerTest, TestTagTwoSockets) {
156 uint64_t sockCookie1;
157 uint64_t sockCookie2;
158 int v4socket1 = setUpSocketAndTag(AF_INET, &sockCookie1, TEST_TAG, TEST_UID, TEST_UID);
159 setUpSocketAndTag(AF_INET, &sockCookie2, TEST_TAG, TEST_UID, TEST_UID);
160 expectUidTag(sockCookie1, TEST_UID, TEST_TAG);
161 expectUidTag(sockCookie2, TEST_UID, TEST_TAG);
162 ASSERT_EQ(0, mBh.untagSocket(v4socket1));
163 expectNoTag(sockCookie1);
164 expectUidTag(sockCookie2, TEST_UID, TEST_TAG);
165 ASSERT_FALSE(mFakeCookieTagMap.getNextKey(sockCookie2).ok());
166 }
167
TEST_F(BpfHandlerTest,TestTagSocketV6)168 TEST_F(BpfHandlerTest, TestTagSocketV6) {
169 uint64_t sockCookie;
170 int v6socket = setUpSocketAndTag(AF_INET6, &sockCookie, TEST_TAG, TEST_UID, TEST_UID);
171 expectUidTag(sockCookie, TEST_UID, TEST_TAG);
172 ASSERT_EQ(0, mBh.untagSocket(v6socket));
173 expectNoTag(sockCookie);
174 expectMapEmpty(mFakeCookieTagMap);
175 }
176
TEST_F(BpfHandlerTest,TestTagInvalidSocket)177 TEST_F(BpfHandlerTest, TestTagInvalidSocket) {
178 int invalidSocket = -1;
179 ASSERT_GT(0, mBh.tagSocket(invalidSocket, TEST_TAG, TEST_UID, TEST_UID));
180 expectMapEmpty(mFakeCookieTagMap);
181 }
182
TEST_F(BpfHandlerTest,TestTagSocketWithUnsupportedFamily)183 TEST_F(BpfHandlerTest, TestTagSocketWithUnsupportedFamily) {
184 int packetSocket = socket(AF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
185 EXPECT_LE(0, packetSocket);
186 EXPECT_NE(NONEXISTENT_COOKIE, getSocketCookie(packetSocket));
187 EXPECT_EQ(-EAFNOSUPPORT, mBh.tagSocket(packetSocket, TEST_TAG, TEST_UID, TEST_UID));
188 }
189
TEST_F(BpfHandlerTest,TestTagSocketWithUnsupportedProtocol)190 TEST_F(BpfHandlerTest, TestTagSocketWithUnsupportedProtocol) {
191 int rawSocket = socket(AF_INET, SOCK_RAW | SOCK_CLOEXEC, IPPROTO_RAW);
192 EXPECT_LE(0, rawSocket);
193 EXPECT_NE(NONEXISTENT_COOKIE, getSocketCookie(rawSocket));
194 EXPECT_EQ(-EPROTONOSUPPORT, mBh.tagSocket(rawSocket, TEST_TAG, TEST_UID, TEST_UID));
195 }
196
TEST_F(BpfHandlerTest,TestTagSocketWithoutPermission)197 TEST_F(BpfHandlerTest, TestTagSocketWithoutPermission) {
198 int sock = socket(AF_INET6, SOCK_STREAM | SOCK_CLOEXEC, 0);
199 ASSERT_NE(-1, sock);
200 ASSERT_EQ(-EPERM, mBh.tagSocket(sock, TEST_TAG, TEST_UID, TEST_UID2));
201 expectMapEmpty(mFakeCookieTagMap);
202 }
203
TEST_F(BpfHandlerTest,TestTagSocketWithPermission)204 TEST_F(BpfHandlerTest, TestTagSocketWithPermission) {
205 // Grant permission to real uid. In practice, the uid permission map will be updated by
206 // TrafficController::setPermissionForUids().
207 uid_t realUid = TEST_UID2;
208 ASSERT_RESULT_OK(mFakeUidPermissionMap.writeValue(realUid,
209 BPF_PERMISSION_UPDATE_DEVICE_STATS, BPF_ANY));
210
211 // Tag a socket to a different uid other then realUid.
212 uint64_t sockCookie;
213 int v6socket = setUpSocketAndTag(AF_INET6, &sockCookie, TEST_TAG, TEST_UID, realUid);
214 expectUidTag(sockCookie, TEST_UID, TEST_TAG);
215 EXPECT_EQ(0, mBh.untagSocket(v6socket));
216 expectNoTag(sockCookie);
217 expectMapEmpty(mFakeCookieTagMap);
218
219 // Tag a socket to AID_CLAT other then realUid.
220 int sock = socket(AF_INET6, SOCK_STREAM | SOCK_CLOEXEC, 0);
221 ASSERT_NE(-1, sock);
222 ASSERT_EQ(-EPERM, mBh.tagSocket(sock, TEST_TAG, AID_CLAT, realUid));
223 expectMapEmpty(mFakeCookieTagMap);
224 }
225
TEST_F(BpfHandlerTest,TestUntagInvalidSocket)226 TEST_F(BpfHandlerTest, TestUntagInvalidSocket) {
227 int invalidSocket = -1;
228 ASSERT_GT(0, mBh.untagSocket(invalidSocket));
229 int v4socket = socket(AF_INET, SOCK_STREAM | SOCK_CLOEXEC, 0);
230 ASSERT_GT(0, mBh.untagSocket(v4socket));
231 expectMapEmpty(mFakeCookieTagMap);
232 }
233
TEST_F(BpfHandlerTest,TestTagSocketReachLimitFail)234 TEST_F(BpfHandlerTest, TestTagSocketReachLimitFail) {
235 uid_t uid = TEST_UID;
236 StatsKey tagStatsMapKey[3];
237 for (int i = 0; i < 3; i++) {
238 uint64_t cookie = TEST_COOKIE + i;
239 uint32_t tag = TEST_TAG + i;
240 populateFakeStats(cookie, uid, tag, &tagStatsMapKey[i]);
241 }
242 expectTagSocketReachLimit(TEST_TAG, TEST_UID);
243 }
244
TEST_F(BpfHandlerTest,TestTagSocketReachTotalLimitFail)245 TEST_F(BpfHandlerTest, TestTagSocketReachTotalLimitFail) {
246 StatsKey tagStatsMapKey[4];
247 for (int i = 0; i < 4; i++) {
248 uint64_t cookie = TEST_COOKIE + i;
249 uint32_t tag = TEST_TAG + i;
250 uid_t uid = TEST_UID + i;
251 populateFakeStats(cookie, uid, tag, &tagStatsMapKey[i]);
252 }
253 expectTagSocketReachLimit(TEST_TAG, TEST_UID);
254 }
255
256 } // namespace net
257 } // namespace android
258