1 /*
2  * Copyright (C) 2020 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 <gtest/gtest.h>
18 
19 #include <dirent.h>
20 #include <err.h>
21 #include <errno.h>
22 #include <fcntl.h>
23 #include <netinet/in.h>
24 #include <stdlib.h>
25 #include <sys/epoll.h>
26 #include <sys/eventfd.h>
27 #include <sys/types.h>
28 #include <unistd.h>
29 
30 #if defined(__BIONIC__)
31 #include <sys/pidfd.h>
32 
33 #include "platform/bionic/fdtrack.h"
34 #include "platform/bionic/reserved_signals.h"
35 #endif
36 
37 #include <vector>
38 
39 #include <android-base/cmsg.h>
40 #include <android-base/logging.h>
41 #include <android-base/unique_fd.h>
42 
43 #include "utils.h"
44 
45 using android::base::ReceiveFileDescriptors;
46 using android::base::SendFileDescriptors;
47 using android::base::unique_fd;
48 
49 #if defined(__BIONIC__)
DumpEvent(std::vector<android_fdtrack_event> * events,size_t index)50 void DumpEvent(std::vector<android_fdtrack_event>* events, size_t index) {
51   auto& event = (*events)[index];
52   if (event.type == ANDROID_FDTRACK_EVENT_TYPE_CREATE) {
53     fprintf(stderr, "  event %zu: fd %d created by %s\n", index, event.fd,
54             event.data.create.function_name);
55   } else if (event.type == ANDROID_FDTRACK_EVENT_TYPE_CLOSE) {
56     fprintf(stderr, "  event %zu: fd %d closed\n", index, event.fd);
57   } else {
58     errx(1, "unexpected fdtrack event type: %d", event.type);
59   }
60 }
61 
FdtrackRun(void (* func)(),bool reenable=true)62 std::vector<android_fdtrack_event> FdtrackRun(void (*func)(), bool reenable = true) {
63   // Each bionic test is run in separate process, so we can safely use a static here.
64   // However, since they're all forked, we need to reenable fdtrack.
65   if (reenable) {
66     android_fdtrack_set_globally_enabled(true);
67   }
68 
69   static std::vector<android_fdtrack_event> events;
70   events.clear();
71 
72   android_fdtrack_hook_t previous = nullptr;
73   android_fdtrack_hook_t hook = [](android_fdtrack_event* event) { events.push_back(*event); };
74 
75   if (!android_fdtrack_compare_exchange_hook(&previous, hook)) {
76     errx(1, "failed to exchange hook: previous hook was %p", previous);
77   }
78 
79   if (previous) {
80     errx(1, "hook was already registered?");
81     abort();
82   }
83 
84   func();
85 
86   if (!android_fdtrack_compare_exchange_hook(&hook, nullptr)) {
87     errx(1, "failed to reset hook");
88   }
89 
90   // Filter out temporary fds created and closed as a result of the call.
91   // (e.g. accept creating a socket to tell netd about the newly accepted socket)
92   size_t i = 0;
93   while (i + 1 < events.size()) {
94     auto& event = events[i];
95     if (event.type == ANDROID_FDTRACK_EVENT_TYPE_CREATE) {
96       for (size_t j = i + 1; j < events.size(); ++j) {
97         if (event.fd == events[j].fd) {
98           if (events[j].type == ANDROID_FDTRACK_EVENT_TYPE_CREATE) {
99             fprintf(stderr, "error: multiple create events for the same fd:\n");
100             DumpEvent(&events, i);
101             DumpEvent(&events, j);
102             exit(1);
103           }
104 
105           events.erase(events.begin() + j);
106           events.erase(events.begin() + i);
107           continue;
108         }
109       }
110     }
111     ++i;
112   }
113 
114   return std::move(events);
115 }
116 
FdtrackEventTypeToName(android_fdtrack_event_type event_type)117 const char* FdtrackEventTypeToName(android_fdtrack_event_type event_type) {
118   switch (event_type) {
119     case ANDROID_FDTRACK_EVENT_TYPE_CREATE:
120       return "created";
121     case ANDROID_FDTRACK_EVENT_TYPE_CLOSE:
122       return "closed";
123   }
124 }
125 #endif
126 
TEST(fdtrack,close)127 TEST(fdtrack, close) {
128 #if defined(__BIONIC__)
129   static int fd = open("/dev/null", O_WRONLY | O_CLOEXEC);
130   ASSERT_NE(-1, fd);
131 
132   auto events = FdtrackRun([]() { close(fd); });
133   ASSERT_EQ(1U, events.size());
134   ASSERT_EQ(fd, events[0].fd);
135   ASSERT_EQ(ANDROID_FDTRACK_EVENT_TYPE_CLOSE, events[0].type);
136 #endif
137 }
138 
TEST(fdtrack,fork)139 TEST(fdtrack, fork) {
140 #if defined(__BIONIC__)
141   ASSERT_EXIT(
142       []() {
143         static int fd = open("/dev/null", O_WRONLY | O_CLOEXEC);
144         ASSERT_NE(-1, fd);
145 
146         auto events = FdtrackRun([]() { close(fd); }, false);
147         ASSERT_EQ(0U, events.size());
148         exit(0);
149       }(),
150       testing::ExitedWithCode(0), "");
151 #endif
152 }
153 
TEST(fdtrack,enable_disable)154 TEST(fdtrack, enable_disable) {
155 #if defined(__BIONIC__)
156   static int fd1 = -1;
157   static int fd2 = -1;
158   static int fd3 = -1;
159 
160   auto events = FdtrackRun([]() {
161     if (!android_fdtrack_get_enabled()) {
162       errx(1, "fdtrack is disabled");
163     }
164     fd1 = open("/dev/null", O_WRONLY | O_CLOEXEC);
165     android_fdtrack_set_enabled(false);
166     fd2 = open("/dev/null", O_WRONLY | O_CLOEXEC);
167     android_fdtrack_set_enabled(true);
168     fd3 = open("/dev/null", O_WRONLY | O_CLOEXEC);
169   });
170 
171   if (fd1 == -1 || fd2 == -1 || fd3 == -1) {
172     errx(1, "failed to open /dev/null");
173   }
174 
175   ASSERT_EQ(2U, events.size());
176 
177   ASSERT_EQ(fd1, events[0].fd);
178   ASSERT_EQ(ANDROID_FDTRACK_EVENT_TYPE_CREATE, events[0].type);
179   ASSERT_STREQ("open", events[0].data.create.function_name);
180 
181   ASSERT_EQ(fd3, events[1].fd);
182   ASSERT_EQ(ANDROID_FDTRACK_EVENT_TYPE_CREATE, events[1].type);
183   ASSERT_STREQ("open", events[1].data.create.function_name);
184 #endif
185 }
186 
187 struct require_semicolon;
188 
189 #if defined(__BIONIC__)
SetFdResult(std::vector<int> * output,int fd)190 void SetFdResult(std::vector<int>* output, int fd) {
191   output->push_back(fd);
192 }
193 
SetFdResult(std::vector<int> * output,std::vector<int> fds)194 void SetFdResult(std::vector<int>* output, std::vector<int> fds) {
195   *output = fds;
196 }
197 
198 #define FDTRACK_TEST_NAME(test_name, fdtrack_name, expression)                                   \
199   TEST(fdtrack, test_name) {                                                                     \
200     static std::vector<int> expected_fds;                                                        \
201     auto events = FdtrackRun([]() { SetFdResult(&expected_fds, expression); });                  \
202     for (auto& fd : expected_fds) {                                                              \
203       ASSERT_NE(-1, fd) << strerror(errno);                                                      \
204     }                                                                                            \
205     if (events.size() != expected_fds.size()) {                                                  \
206       fprintf(stderr, "too many events received: expected %zu, got %zu:\n", expected_fds.size(), \
207               events.size());                                                                    \
208       for (size_t i = 0; i < events.size(); ++i) {                                               \
209         DumpEvent(&events, i);                                                                   \
210       }                                                                                          \
211       FAIL();                                                                                    \
212       return;                                                                                    \
213     }                                                                                            \
214     for (auto& event : events) {                                                                 \
215       ASSERT_NE(expected_fds.end(),                                                              \
216                 std::find(expected_fds.begin(), expected_fds.end(), events[0].fd));              \
217       ASSERT_EQ(ANDROID_FDTRACK_EVENT_TYPE_CREATE, event.type);                                  \
218       ASSERT_STREQ(fdtrack_name, event.data.create.function_name);                               \
219     }                                                                                            \
220   }                                                                                              \
221   struct require_semicolon
222 #else
223 #define FDTRACK_TEST_NAME(name, fdtrack_name, expression) \
224   TEST(fdtrack, name) {}                                  \
225   struct require_semicolon
226 #endif
227 
228 #define FDTRACK_TEST(name, expression) FDTRACK_TEST_NAME(name, #name, expression)
229 
230 // clang-format misformats statement expressions pretty badly here:
231 // clang-format off
232 FDTRACK_TEST(open, open("/dev/null", O_WRONLY | O_CLOEXEC));
233 FDTRACK_TEST(openat, openat(AT_EMPTY_PATH, "/dev/null", O_WRONLY | O_CLOEXEC));
234 FDTRACK_TEST(socket, socket(AF_UNIX, SOCK_STREAM, 0));
235 
236 FDTRACK_TEST(pidfd_open, ({
237   int rc = pidfd_open(getpid(), 0);
238   if (rc == -1 && errno == ENOSYS) GTEST_SKIP() << "no pidfd_open() in this kernel";
239   ASSERT_NE(-1, rc) << strerror(errno);
240   rc;
241 }));
242 
243 FDTRACK_TEST(pidfd_getfd, ({
244   android_fdtrack_set_enabled(false);
245   int pidfd_self = pidfd_open(getpid(), 0);
246   if (pidfd_self == -1 && errno == ENOSYS) GTEST_SKIP() << "no pidfd_open() in this kernel";
247   ASSERT_NE(-1, pidfd_self) << strerror(errno);
248 
249   android_fdtrack_set_enabled(true);
250 
251   int rc = pidfd_getfd(pidfd_self, STDIN_FILENO, 0);
252   if (rc == -1 && errno == ENOSYS) GTEST_SKIP() << "no pidfd_getfd() in this kernel";
253   ASSERT_NE(-1, rc) << strerror(errno);
254 
255   android_fdtrack_set_enabled(false);
256   close(pidfd_self);
257   android_fdtrack_set_enabled(true);
258 
259   rc;
260 }));
261 
262 FDTRACK_TEST(dup, dup(STDOUT_FILENO));
263 FDTRACK_TEST(dup2, dup2(STDOUT_FILENO, STDERR_FILENO));
264 FDTRACK_TEST(dup3, dup3(STDOUT_FILENO, STDERR_FILENO, 0));
265 FDTRACK_TEST_NAME(fcntl_F_DUPFD, "F_DUPFD", fcntl(STDOUT_FILENO, F_DUPFD, 0));
266 FDTRACK_TEST_NAME(fcntl_F_DUPFD_CLOEXEC, "F_DUPFD_CLOEXEC", fcntl(STDOUT_FILENO, F_DUPFD_CLOEXEC, 0));
267 
268 FDTRACK_TEST(pipe, ({
269   std::vector<int> fds = { -1, -1};
270   if (pipe(fds.data()) != 0) {
271     err(1, "pipe failed");
272   }
273   fds;
274 }));
275 
276 FDTRACK_TEST(pipe2, ({
277   std::vector<int> fds = { -1, -1};
278   if (pipe2(fds.data(), O_CLOEXEC) != 0) {
279     err(1, "pipe failed");
280   }
281   fds;
282 }));
283 
284 FDTRACK_TEST(socketpair, ({
285   std::vector<int> fds = { -1, -1};
286   if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, fds.data()) != 0) {
287     err(1, "socketpair failed");
288   }
289   fds;
290 }));
291 
292 FDTRACK_TEST(epoll_create, epoll_create(1));
293 FDTRACK_TEST(epoll_create1, epoll_create1(0));
294 
295 FDTRACK_TEST(eventfd, eventfd(0, 0));
296 
297 #if defined(__BIONIC__)
CreateListener()298 static int CreateListener() {
299   android_fdtrack_set_enabled(false);
300   int listener = socket(AF_INET, SOCK_STREAM, 0);
301   CHECK_NE(-1, listener);
302 
303   sockaddr_in addr = {
304       .sin_family = AF_INET,
305       .sin_port = 0,
306       .sin_addr = {htonl(INADDR_LOOPBACK)},
307   };
308   socklen_t addrlen = sizeof(addr);
309 
310   CHECK_NE(-1, bind(listener, reinterpret_cast<sockaddr*>(&addr), addrlen)) << strerror(errno);
311   CHECK_NE(-1, getsockname(listener, reinterpret_cast<sockaddr*>(&addr), &addrlen));
312   CHECK_EQ(static_cast<size_t>(addrlen), sizeof(addr));
313   CHECK_NE(-1, listen(listener, 1));
314 
315   int connector = socket(AF_INET, SOCK_STREAM, 0);
316   CHECK_NE(-1, connector);
317   CHECK_NE(-1, connect(connector, reinterpret_cast<sockaddr*>(&addr), addrlen));
318   android_fdtrack_set_enabled(true);
319 
320   return listener;
321 }
322 #endif
323 
324 FDTRACK_TEST_NAME(accept, "accept4", accept(CreateListener(), nullptr, nullptr));
325 FDTRACK_TEST(accept4, accept4(CreateListener(), nullptr, nullptr, 0));
326 
327 FDTRACK_TEST(recvmsg, ({
328   android_fdtrack_set_enabled(false);
329   int sockets[2];
330   ASSERT_NE(-1, socketpair(AF_UNIX, SOCK_SEQPACKET, 0, sockets));
331   ASSERT_EQ(3, SendFileDescriptors(sockets[0], "foo", 3, STDIN_FILENO));
332   android_fdtrack_set_enabled(true);
333 
334   char buf[4];
335   unique_fd received_fd;
336   ASSERT_EQ(3, ReceiveFileDescriptors(sockets[1], buf, sizeof(buf), &received_fd));
337   received_fd.release();
338 }));
339 
340 FDTRACK_TEST_NAME(vfork, "open", ({
341   int fd = open("/dev/null", O_RDONLY);
342 
343   pid_t rc = vfork();
344   ASSERT_NE(-1, rc);
345 
346   if (rc == 0) {
347     close(fd);
348     _exit(0);
349   }
350 
351   int status;
352   pid_t wait_result = waitpid(rc, &status, 0);
353   ASSERT_EQ(wait_result, rc);
354   ASSERT_TRUE(WIFEXITED(status));
355   ASSERT_EQ(0, WEXITSTATUS(status));
356 
357   fd;
358 }));
359 // clang-format on
360