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 using android::base::ReceiveFileDescriptors;
44 using android::base::SendFileDescriptors;
45 using android::base::unique_fd;
46 
47 #if defined(__BIONIC__)
DumpEvent(std::vector<android_fdtrack_event> * events,size_t index)48 void DumpEvent(std::vector<android_fdtrack_event>* events, size_t index) {
49   auto& event = (*events)[index];
50   if (event.type == ANDROID_FDTRACK_EVENT_TYPE_CREATE) {
51     fprintf(stderr, "  event %zu: fd %d created by %s\n", index, event.fd,
52             event.data.create.function_name);
53   } else if (event.type == ANDROID_FDTRACK_EVENT_TYPE_CLOSE) {
54     fprintf(stderr, "  event %zu: fd %d closed\n", index, event.fd);
55   } else {
56     errx(1, "unexpected fdtrack event type: %d", event.type);
57   }
58 }
59 
FdtrackRun(void (* func)(),bool reenable=true)60 std::vector<android_fdtrack_event> FdtrackRun(void (*func)(), bool reenable = true) {
61   // Each bionic test is run in separate process, so we can safely use a static here.
62   // However, since they're all forked, we need to reenable fdtrack.
63   if (reenable) {
64     android_fdtrack_set_globally_enabled(true);
65   }
66 
67   static std::vector<android_fdtrack_event> events;
68   events.clear();
69 
70   android_fdtrack_hook_t previous = nullptr;
71   android_fdtrack_hook_t hook = [](android_fdtrack_event* event) { events.push_back(*event); };
72 
73   if (!android_fdtrack_compare_exchange_hook(&previous, hook)) {
74     errx(1, "failed to exchange hook: previous hook was %p", previous);
75   }
76 
77   if (previous) {
78     errx(1, "hook was already registered?");
79     abort();
80   }
81 
82   func();
83 
84   if (!android_fdtrack_compare_exchange_hook(&hook, nullptr)) {
85     errx(1, "failed to reset hook");
86   }
87 
88   // Filter out temporary fds created and closed as a result of the call.
89   // (e.g. accept creating a socket to tell netd about the newly accepted socket)
90   size_t i = 0;
91   while (i + 1 < events.size()) {
92     auto& event = events[i];
93     if (event.type == ANDROID_FDTRACK_EVENT_TYPE_CREATE) {
94       for (size_t j = i + 1; j < events.size(); ++j) {
95         if (event.fd == events[j].fd) {
96           if (events[j].type == ANDROID_FDTRACK_EVENT_TYPE_CREATE) {
97             fprintf(stderr, "error: multiple create events for the same fd:\n");
98             DumpEvent(&events, i);
99             DumpEvent(&events, j);
100             exit(1);
101           }
102 
103           events.erase(events.begin() + j);
104           events.erase(events.begin() + i);
105           continue;
106         }
107       }
108     }
109     ++i;
110   }
111 
112   return std::move(events);
113 }
114 
FdtrackEventTypeToName(android_fdtrack_event_type event_type)115 const char* FdtrackEventTypeToName(android_fdtrack_event_type event_type) {
116   switch (event_type) {
117     case ANDROID_FDTRACK_EVENT_TYPE_CREATE:
118       return "created";
119     case ANDROID_FDTRACK_EVENT_TYPE_CLOSE:
120       return "closed";
121   }
122 }
123 #endif
124 
TEST(fdtrack,close)125 TEST(fdtrack, close) {
126 #if defined(__BIONIC__)
127   static int fd = open("/dev/null", O_WRONLY | O_CLOEXEC);
128   ASSERT_NE(-1, fd);
129 
130   auto events = FdtrackRun([]() { close(fd); });
131   ASSERT_EQ(1U, events.size());
132   ASSERT_EQ(fd, events[0].fd);
133   ASSERT_EQ(ANDROID_FDTRACK_EVENT_TYPE_CLOSE, events[0].type);
134 #endif
135 }
136 
TEST(fdtrack,fork)137 TEST(fdtrack, fork) {
138 #if defined(__BIONIC__)
139   ASSERT_EXIT(
140       []() {
141         static int fd = open("/dev/null", O_WRONLY | O_CLOEXEC);
142         ASSERT_NE(-1, fd);
143 
144         auto events = FdtrackRun([]() { close(fd); }, false);
145         ASSERT_EQ(0U, events.size());
146         exit(0);
147       }(),
148       testing::ExitedWithCode(0), "");
149 #endif
150 }
151 
TEST(fdtrack,enable_disable)152 TEST(fdtrack, enable_disable) {
153 #if defined(__BIONIC__)
154   static int fd1 = -1;
155   static int fd2 = -1;
156   static int fd3 = -1;
157 
158   auto events = FdtrackRun([]() {
159     if (!android_fdtrack_get_enabled()) {
160       errx(1, "fdtrack is disabled");
161     }
162     fd1 = open("/dev/null", O_WRONLY | O_CLOEXEC);
163     android_fdtrack_set_enabled(false);
164     fd2 = open("/dev/null", O_WRONLY | O_CLOEXEC);
165     android_fdtrack_set_enabled(true);
166     fd3 = open("/dev/null", O_WRONLY | O_CLOEXEC);
167   });
168 
169   if (fd1 == -1 || fd2 == -1 || fd3 == -1) {
170     errx(1, "failed to open /dev/null");
171   }
172 
173   ASSERT_EQ(2U, events.size());
174 
175   ASSERT_EQ(fd1, events[0].fd);
176   ASSERT_EQ(ANDROID_FDTRACK_EVENT_TYPE_CREATE, events[0].type);
177   ASSERT_STREQ("open", events[0].data.create.function_name);
178 
179   ASSERT_EQ(fd3, events[1].fd);
180   ASSERT_EQ(ANDROID_FDTRACK_EVENT_TYPE_CREATE, events[1].type);
181   ASSERT_STREQ("open", events[1].data.create.function_name);
182 #endif
183 }
184 
185 struct require_semicolon;
186 
187 #if defined(__BIONIC__)
SetFdResult(std::vector<int> * output,int fd)188 void SetFdResult(std::vector<int>* output, int fd) {
189   output->push_back(fd);
190 }
191 
SetFdResult(std::vector<int> * output,std::vector<int> fds)192 void SetFdResult(std::vector<int>* output, std::vector<int> fds) {
193   *output = fds;
194 }
195 
196 #define FDTRACK_TEST_NAME(test_name, fdtrack_name, expression)                                   \
197   TEST(fdtrack, test_name) {                                                                     \
198     static std::vector<int> expected_fds;                                                        \
199     auto events = FdtrackRun([]() { SetFdResult(&expected_fds, expression); });                  \
200     for (auto& fd : expected_fds) {                                                              \
201       ASSERT_NE(-1, fd) << strerror(errno);                                                      \
202     }                                                                                            \
203     if (events.size() != expected_fds.size()) {                                                  \
204       fprintf(stderr, "too many events received: expected %zu, got %zu:\n", expected_fds.size(), \
205               events.size());                                                                    \
206       for (size_t i = 0; i < events.size(); ++i) {                                               \
207         DumpEvent(&events, i);                                                                   \
208       }                                                                                          \
209       FAIL();                                                                                    \
210       return;                                                                                    \
211     }                                                                                            \
212     for (auto& event : events) {                                                                 \
213       ASSERT_NE(expected_fds.end(),                                                              \
214                 std::find(expected_fds.begin(), expected_fds.end(), events[0].fd));              \
215       ASSERT_EQ(ANDROID_FDTRACK_EVENT_TYPE_CREATE, event.type);                                  \
216       ASSERT_STREQ(fdtrack_name, event.data.create.function_name);                               \
217     }                                                                                            \
218   }                                                                                              \
219   struct require_semicolon
220 #else
221 #define FDTRACK_TEST_NAME(name, fdtrack_name, expression) \
222   TEST(fdtrack, name) {}                                  \
223   struct require_semicolon
224 #endif
225 
226 #define FDTRACK_TEST(name, expression) FDTRACK_TEST_NAME(name, #name, expression)
227 
228 // clang-format misformats statement expressions pretty badly here:
229 // clang-format off
230 FDTRACK_TEST(open, open("/dev/null", O_WRONLY | O_CLOEXEC));
231 FDTRACK_TEST(openat, openat(AT_EMPTY_PATH, "/dev/null", O_WRONLY | O_CLOEXEC));
232 FDTRACK_TEST(socket, socket(AF_UNIX, SOCK_STREAM, 0));
233 
234 FDTRACK_TEST(pidfd_open, ({
235   int rc = pidfd_open(getpid(), 0);
236   if (rc == -1) {
237     ASSERT_EQ(ENOSYS, errno);
238     GTEST_SKIP() << "pidfd_open not available";
239   }
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) {
247     ASSERT_EQ(ENOSYS, errno);
248     GTEST_SKIP() << "pidfd_open not available";
249   }
250   android_fdtrack_set_enabled(true);
251 
252   int rc = pidfd_getfd(pidfd_self, STDIN_FILENO, 0);
253   if (rc == -1) {
254     ASSERT_EQ(ENOSYS, errno);
255     GTEST_SKIP() << "pidfd_getfd not available";
256   }
257 
258   android_fdtrack_set_enabled(false);
259   close(pidfd_self);
260   android_fdtrack_set_enabled(true);
261 
262   rc;
263 }));
264 
265 FDTRACK_TEST(dup, dup(STDOUT_FILENO));
266 FDTRACK_TEST(dup2, dup2(STDOUT_FILENO, STDERR_FILENO));
267 FDTRACK_TEST(dup3, dup3(STDOUT_FILENO, STDERR_FILENO, 0));
268 FDTRACK_TEST_NAME(fcntl_F_DUPFD, "F_DUPFD", fcntl(STDOUT_FILENO, F_DUPFD, 0));
269 FDTRACK_TEST_NAME(fcntl_F_DUPFD_CLOEXEC, "F_DUPFD_CLOEXEC", fcntl(STDOUT_FILENO, F_DUPFD_CLOEXEC, 0));
270 
271 FDTRACK_TEST(pipe, ({
272   std::vector<int> fds = { -1, -1};
273   if (pipe(fds.data()) != 0) {
274     err(1, "pipe failed");
275   }
276   fds;
277 }));
278 
279 FDTRACK_TEST(pipe2, ({
280   std::vector<int> fds = { -1, -1};
281   if (pipe2(fds.data(), O_CLOEXEC) != 0) {
282     err(1, "pipe failed");
283   }
284   fds;
285 }));
286 
287 FDTRACK_TEST(socketpair, ({
288   std::vector<int> fds = { -1, -1};
289   if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, fds.data()) != 0) {
290     err(1, "socketpair failed");
291   }
292   fds;
293 }));
294 
295 FDTRACK_TEST(epoll_create, epoll_create(1));
296 FDTRACK_TEST(epoll_create1, epoll_create1(0));
297 
298 FDTRACK_TEST(eventfd, eventfd(0, 0));
299 
300 #if defined(__BIONIC__)
CreateListener()301 static int CreateListener() {
302   android_fdtrack_set_enabled(false);
303   int listener = socket(AF_INET, SOCK_STREAM, 0);
304   CHECK_NE(-1, listener);
305 
306   sockaddr_in addr = {
307       .sin_family = AF_INET,
308       .sin_port = 0,
309       .sin_addr = {htonl(INADDR_LOOPBACK)},
310   };
311   socklen_t addrlen = sizeof(addr);
312 
313   CHECK_NE(-1, bind(listener, reinterpret_cast<sockaddr*>(&addr), addrlen)) << strerror(errno);
314   CHECK_NE(-1, getsockname(listener, reinterpret_cast<sockaddr*>(&addr), &addrlen));
315   CHECK_EQ(static_cast<size_t>(addrlen), sizeof(addr));
316   CHECK_NE(-1, listen(listener, 1));
317 
318   int connector = socket(AF_INET, SOCK_STREAM, 0);
319   CHECK_NE(-1, connector);
320   CHECK_NE(-1, connect(connector, reinterpret_cast<sockaddr*>(&addr), addrlen));
321   android_fdtrack_set_enabled(true);
322 
323   return listener;
324 }
325 #endif
326 
327 FDTRACK_TEST_NAME(accept, "accept4", accept(CreateListener(), nullptr, nullptr));
328 FDTRACK_TEST(accept4, accept4(CreateListener(), nullptr, nullptr, 0));
329 
330 FDTRACK_TEST(recvmsg, ({
331   android_fdtrack_set_enabled(false);
332   int sockets[2];
333   ASSERT_NE(-1, socketpair(AF_UNIX, SOCK_SEQPACKET, 0, sockets));
334   ASSERT_EQ(3, SendFileDescriptors(sockets[0], "foo", 3, STDIN_FILENO));
335   android_fdtrack_set_enabled(true);
336 
337   char buf[4];
338   unique_fd received_fd;
339   ASSERT_EQ(3, ReceiveFileDescriptors(sockets[1], buf, sizeof(buf), &received_fd));
340   received_fd.release();
341 }));
342 
343 FDTRACK_TEST_NAME(vfork, "open", ({
344   int fd = open("/dev/null", O_RDONLY);
345 
346   pid_t rc = vfork();
347   ASSERT_NE(-1, rc);
348 
349   if (rc == 0) {
350     close(fd);
351     _exit(0);
352   }
353 
354   int status;
355   pid_t wait_result = waitpid(rc, &status, 0);
356   ASSERT_EQ(wait_result, rc);
357   ASSERT_TRUE(WIFEXITED(status));
358   ASSERT_EQ(0, WEXITSTATUS(status));
359 
360   fd;
361 }));
362 // clang-format on
363