ipc/ipc_send_fds_test.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "build/build_config.h"
   6
   7 #if defined(OS_POSIX)
   8 #if defined(OS_MACOSX)
   9 extern "C" {
  10 #include <sandbox.h>
  11 }
  12 #endif
  13 #include <fcntl.h>
  14 #include <sys/socket.h>
  15 #include <sys/stat.h>
  16 #include <unistd.h>
  17
  18 #include <queue>
  19
  20 #include "base/callback.h"
  21 #include "base/file_descriptor_posix.h"
  22 #include "base/location.h"
  23 #include "base/pickle.h"
  24 #include "base/posix/eintr_wrapper.h"
  25 #include "base/single_thread_task_runner.h"
  26 #include "base/synchronization/waitable_event.h"
  27 #include "ipc/ipc_message_attachment_set.h"
  28 #include "ipc/ipc_message_utils.h"
  29 #include "ipc/ipc_test_base.h"
  30
  31 #if defined(OS_POSIX)
  32 #include "base/macros.h"
  33 #endif
  34
  35 namespace {
  36
  37 const unsigned kNumFDsToSend = 7;  // per message
  38 const unsigned kNumMessages = 20;
  39 const char* kDevZeroPath = "/dev/zero";
  40
  41 #if defined(OS_POSIX)
  42 static_assert(kNumFDsToSend ==
  43                   IPC::MessageAttachmentSet::kMaxDescriptorsPerMessage,
  44               "The number of FDs to send must be kMaxDescriptorsPerMessage.");
  45 #endif
  46
  47 class MyChannelDescriptorListenerBase : public IPC::Listener {
  48  public:
  49   bool OnMessageReceived(const IPC::Message& message) override {
  50     base::PickleIterator iter(message);
  51     base::FileDescriptor descriptor;
  52     while (IPC::ParamTraits<base::FileDescriptor>::Read(
  53                &message, &iter, &descriptor)) {
  54       HandleFD(descriptor.fd);
  55     }
  56     return true;
  57   }
  58
  59  protected:
  60   virtual void HandleFD(int fd) = 0;
  61 };
  62
  63 class MyChannelDescriptorListener : public MyChannelDescriptorListenerBase {
  64  public:
  65   explicit MyChannelDescriptorListener(ino_t expected_inode_num)
  66       : MyChannelDescriptorListenerBase(),
  67         expected_inode_num_(expected_inode_num),
  68         num_fds_received_(0) {
  69   }
  70
  71   bool GotExpectedNumberOfDescriptors() const {
  72     return num_fds_received_ == kNumFDsToSend * kNumMessages;
  73   }
  74
  75   void OnChannelError() override {
  76     base::MessageLoop::current()->Quit();
  77   }
  78
  79  protected:
  80   void HandleFD(int fd) override {
  81     ASSERT_GE(fd, 0);
  82     // Check that we can read from the FD.
  83     char buf;
  84     ssize_t amt_read = read(fd, &buf, 1);
  85     ASSERT_EQ(amt_read, 1);
  86     ASSERT_EQ(buf, 0);  // /dev/zero always reads 0 bytes.
  87
  88     struct stat st;
  89     ASSERT_EQ(fstat(fd, &st), 0);
  90
  91     ASSERT_EQ(close(fd), 0);
  92
  93     // Compare inode numbers to check that the file sent over the wire is
  94     // actually the one expected.
  95     ASSERT_EQ(expected_inode_num_, st.st_ino);
  96
  97     ++num_fds_received_;
  98     if (num_fds_received_ == kNumFDsToSend * kNumMessages)
  99       base::MessageLoop::current()->Quit();
 100   }
 101
 102  private:
 103   ino_t expected_inode_num_;
 104   unsigned num_fds_received_;
 105 };
 106
 107
 108 class IPCSendFdsTest : public IPCTestBase {
 109  protected:
 110   void RunServer() {
 111     // Set up IPC channel and start client.
 112     MyChannelDescriptorListener listener(-1);
 113     CreateChannel(&listener);
 114     ASSERT_TRUE(ConnectChannel());
 115     ASSERT_TRUE(StartClient());
 116
 117     for (unsigned i = 0; i < kNumMessages; ++i) {
 118       IPC::Message* message =
 119           new IPC::Message(0, 3, IPC::Message::PRIORITY_NORMAL);
 120       for (unsigned j = 0; j < kNumFDsToSend; ++j) {
 121         const int fd = open(kDevZeroPath, O_RDONLY);
 122         ASSERT_GE(fd, 0);
 123         base::FileDescriptor descriptor(fd, true);
 124         IPC::ParamTraits<base::FileDescriptor>::Write(message, descriptor);
 125       }
 126       ASSERT_TRUE(sender()->Send(message));
 127     }
 128
 129     // Run message loop.
 130     base::MessageLoop::current()->Run();
 131
 132     // Close the channel so the client's OnChannelError() gets fired.
 133     channel()->Close();
 134
 135     EXPECT_TRUE(WaitForClientShutdown());
 136     DestroyChannel();
 137   }
 138 };
 139
 140 #if defined(OS_ANDROID)
 141 #define MAYBE_DescriptorTest DISABLED_DescriptorTest
 142 #else
 143 #define MAYBE_DescriptorTest DescriptorTest
 144 #endif
 145 TEST_F(IPCSendFdsTest, MAYBE_DescriptorTest) {
 146   Init("SendFdsClient");
 147   RunServer();
 148 }
 149
 150 int SendFdsClientCommon(const std::string& test_client_name,
 151                         ino_t expected_inode_num) {
 152   base::MessageLoopForIO main_message_loop;
 153   MyChannelDescriptorListener listener(expected_inode_num);
 154
 155   // Set up IPC channel.
 156   scoped_ptr<IPC::Channel> channel(IPC::Channel::CreateClient(
 157       IPCTestBase::GetChannelName(test_client_name), &listener, nullptr));
 158   CHECK(channel->Connect());
 159
 160   // Run message loop.
 161   base::MessageLoop::current()->Run();
 162
 163   // Verify that the message loop was exited due to getting the correct number
 164   // of descriptors, and not because of the channel closing unexpectedly.
 165   CHECK(listener.GotExpectedNumberOfDescriptors());
 166
 167   return 0;
 168 }
 169
 170 MULTIPROCESS_IPC_TEST_CLIENT_MAIN(SendFdsClient) {
 171   struct stat st;
 172   int fd = open(kDevZeroPath, O_RDONLY);
 173   fstat(fd, &st);
 174   EXPECT_GE(IGNORE_EINTR(close(fd)), 0);
 175   return SendFdsClientCommon("SendFdsClient", st.st_ino);
 176 }
 177
 178 #if defined(OS_MACOSX)
 179 // Test that FDs are correctly sent to a sandboxed process.
 180 // TODO(port): Make this test cross-platform.
 181 TEST_F(IPCSendFdsTest, DescriptorTestSandboxed) {
 182   Init("SendFdsSandboxedClient");
 183   RunServer();
 184 }
 185
 186 MULTIPROCESS_IPC_TEST_CLIENT_MAIN(SendFdsSandboxedClient) {
 187   struct stat st;
 188   const int fd = open(kDevZeroPath, O_RDONLY);
 189   fstat(fd, &st);
 190   if (IGNORE_EINTR(close(fd)) < 0)
 191     return -1;
 192
 193   // Enable the sandbox.
 194   char* error_buff = NULL;
 195   int error = sandbox_init(kSBXProfilePureComputation, SANDBOX_NAMED,
 196                            &error_buff);
 197   bool success = (error == 0 && error_buff == NULL);
 198   if (!success)
 199     return -1;
 200
 201   sandbox_free_error(error_buff);
 202
 203   // Make sure sandbox is really enabled.
 204   if (open(kDevZeroPath, O_RDONLY) != -1) {
 205     LOG(ERROR) << "Sandbox wasn't properly enabled";
 206     return -1;
 207   }
 208
 209   // See if we can receive a file descriptor.
 210   return SendFdsClientCommon("SendFdsSandboxedClient", st.st_ino);
 211 }
 212 #endif  // defined(OS_MACOSX)
 213
 214
 215 class MyCBListener : public MyChannelDescriptorListenerBase {
 216  public:
 217   MyCBListener(base::Callback<void(int)> cb, int fds_to_send)
 218       : MyChannelDescriptorListenerBase(),
 219         cb_(cb) {
 220     }
 221
 222  protected:
 223   void HandleFD(int fd) override { cb_.Run(fd); }
 224  private:
 225   base::Callback<void(int)> cb_;
 226 };
 227
 228 std::pair<int, int> make_socket_pair() {
 229   int pipe_fds[2];
 230   CHECK_EQ(0, HANDLE_EINTR(socketpair(AF_UNIX, SOCK_STREAM, 0, pipe_fds)));
 231   return std::pair<int, int>(pipe_fds[0], pipe_fds[1]);
 232 }
 233
 234 static void null_cb(int unused_fd) {
 235   NOTREACHED();
 236 }
 237
 238 class PipeChannelHelper {
 239  public:
 240   PipeChannelHelper(base::Thread* in_thread,
 241                     base::Thread* out_thread,
 242                     base::Callback<void(int)> cb,
 243                     int fds_to_send) :
 244       in_thread_(in_thread),
 245       out_thread_(out_thread),
 246       cb_listener_(cb, fds_to_send),
 247       null_listener_(base::Bind(&null_cb), 0) {
 248   }
 249
 250   void Init() {
 251     IPC::ChannelHandle in_handle("IN");
 252     in = IPC::Channel::CreateServer(in_handle, &null_listener_, nullptr);
 253     IPC::ChannelHandle out_handle(
 254         "OUT", base::FileDescriptor(in->TakeClientFileDescriptor()));
 255     out = IPC::Channel::CreateClient(out_handle, &cb_listener_, nullptr);
 256     // PostTask the connect calls to make sure the callbacks happens
 257     // on the right threads.
 258     in_thread_->task_runner()->PostTask(
 259         FROM_HERE, base::Bind(&PipeChannelHelper::Connect, in.get()));
 260     out_thread_->task_runner()->PostTask(
 261         FROM_HERE, base::Bind(&PipeChannelHelper::Connect, out.get()));
 262   }
 263
 264   static void DestroyChannel(scoped_ptr<IPC::Channel> *c,
 265                              base::WaitableEvent *event) {
 266     c->reset(0);
 267     event->Signal();
 268   }
 269
 270   ~PipeChannelHelper() {
 271     base::WaitableEvent a(true, false);
 272     base::WaitableEvent b(true, false);
 273     in_thread_->task_runner()->PostTask(
 274         FROM_HERE, base::Bind(&PipeChannelHelper::DestroyChannel, &in, &a));
 275     out_thread_->task_runner()->PostTask(
 276         FROM_HERE, base::Bind(&PipeChannelHelper::DestroyChannel, &out, &b));
 277     a.Wait();
 278     b.Wait();
 279   }
 280
 281   static void Connect(IPC::Channel *channel) {
 282     EXPECT_TRUE(channel->Connect());
 283   }
 284
 285   void Send(int fd) {
 286     CHECK_EQ(base::MessageLoop::current(), in_thread_->message_loop());
 287
 288     ASSERT_GE(fd, 0);
 289     base::FileDescriptor descriptor(fd, true);
 290
 291     IPC::Message* message =
 292         new IPC::Message(0, 3, IPC::Message::PRIORITY_NORMAL);
 293     IPC::ParamTraits<base::FileDescriptor>::Write(message, descriptor);
 294     ASSERT_TRUE(in->Send(message));
 295   }
 296
 297  private:
 298   scoped_ptr<IPC::Channel> in, out;
 299   base::Thread* in_thread_;
 300   base::Thread* out_thread_;
 301   MyCBListener cb_listener_;
 302   MyCBListener null_listener_;
 303 };
 304
 305 // This test is meant to provoke a kernel bug on OSX, and to prove
 306 // that the workaround for it is working. It sets up two pipes and three
 307 // threads, the producer thread creates socketpairs and sends one of the fds
 308 // over pipe1 to the middleman thread. The middleman thread simply takes the fd
 309 // sends it over pipe2 to the consumer thread. The consumer thread writes a byte
 310 // to each fd it receives and then closes the pipe. The producer thread reads
 311 // the bytes back from each pair of pipes and make sure that everything worked.
 312 // This feedback mechanism makes sure that not too many file descriptors are
 313 // in flight at the same time. For more info on the bug, see:
 314 // http://crbug.com/298276
 315 class IPCMultiSendingFdsTest : public testing::Test {
 316  public:
 317   IPCMultiSendingFdsTest() : received_(true, false) {}
 318
 319   void Producer(PipeChannelHelper* dest,
 320                 base::Thread* t,
 321                 int pipes_to_send) {
 322     for (int i = 0; i < pipes_to_send; i++) {
 323       received_.Reset();
 324       std::pair<int, int> pipe_fds = make_socket_pair();
 325       t->task_runner()->PostTask(
 326           FROM_HERE, base::Bind(&PipeChannelHelper::Send,
 327                                 base::Unretained(dest), pipe_fds.second));
 328       char tmp = 'x';
 329       CHECK_EQ(1, HANDLE_EINTR(write(pipe_fds.first, &tmp, 1)));
 330       CHECK_EQ(0, IGNORE_EINTR(close(pipe_fds.first)));
 331       received_.Wait();
 332     }
 333   }
 334
 335   void ConsumerHandleFD(int fd) {
 336     char tmp = 'y';
 337     CHECK_EQ(1, HANDLE_EINTR(read(fd, &tmp, 1)));
 338     CHECK_EQ(tmp, 'x');
 339     CHECK_EQ(0, IGNORE_EINTR(close(fd)));
 340     received_.Signal();
 341   }
 342
 343   base::Thread* CreateThread(const char* name) {
 344     base::Thread* ret = new base::Thread(name);
 345     base::Thread::Options options;
 346     options.message_loop_type = base::MessageLoop::TYPE_IO;
 347     ret->StartWithOptions(options);
 348     return ret;
 349   }
 350
 351   void Run() {
 352     // On my mac, this test fails roughly 35 times per
 353     // million sends with low load, but much more with high load.
 354     // Unless the workaround is in place. With 10000 sends, we
 355     // should see at least a 3% failure rate.
 356     const int pipes_to_send = 20000;
 357     scoped_ptr<base::Thread> producer(CreateThread("producer"));
 358     scoped_ptr<base::Thread> middleman(CreateThread("middleman"));
 359     scoped_ptr<base::Thread> consumer(CreateThread("consumer"));
 360     PipeChannelHelper pipe1(
 361         middleman.get(),
 362         consumer.get(),
 363         base::Bind(&IPCMultiSendingFdsTest::ConsumerHandleFD,
 364                    base::Unretained(this)),
 365         pipes_to_send);
 366     PipeChannelHelper pipe2(
 367         producer.get(),
 368         middleman.get(),
 369         base::Bind(&PipeChannelHelper::Send, base::Unretained(&pipe1)),
 370         pipes_to_send);
 371     pipe1.Init();
 372     pipe2.Init();
 373     Producer(&pipe2, producer.get(), pipes_to_send);
 374   }
 375
 376  private:
 377   base::WaitableEvent received_;
 378 };
 379
 380 TEST_F(IPCMultiSendingFdsTest, StressTest) {
 381   Run();
 382 }
 383
 384 }  // namespace
 385
 386 #endif  // defined(OS_POSIX)