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 TEST_F(IPCSendFdsTest, DescriptorTest) {
 141   Init("SendFdsClient");
 142   RunServer();
 143 }
 144
 145 int SendFdsClientCommon(const std::string& test_client_name,
 146                         ino_t expected_inode_num) {
 147   base::MessageLoopForIO main_message_loop;
 148   MyChannelDescriptorListener listener(expected_inode_num);
 149
 150   // Set up IPC channel.
 151   scoped_ptr<IPC::Channel> channel(IPC::Channel::CreateClient(
 152       IPCTestBase::GetChannelName(test_client_name), &listener, nullptr));
 153   CHECK(channel->Connect());
 154
 155   // Run message loop.
 156   base::MessageLoop::current()->Run();
 157
 158   // Verify that the message loop was exited due to getting the correct number
 159   // of descriptors, and not because of the channel closing unexpectedly.
 160   CHECK(listener.GotExpectedNumberOfDescriptors());
 161
 162   return 0;
 163 }
 164
 165 MULTIPROCESS_IPC_TEST_CLIENT_MAIN(SendFdsClient) {
 166   struct stat st;
 167   int fd = open(kDevZeroPath, O_RDONLY);
 168   fstat(fd, &st);
 169   EXPECT_GE(IGNORE_EINTR(close(fd)), 0);
 170   return SendFdsClientCommon("SendFdsClient", st.st_ino);
 171 }
 172
 173 #if defined(OS_MACOSX)
 174 // Test that FDs are correctly sent to a sandboxed process.
 175 // TODO(port): Make this test cross-platform.
 176 TEST_F(IPCSendFdsTest, DescriptorTestSandboxed) {
 177   Init("SendFdsSandboxedClient");
 178   RunServer();
 179 }
 180
 181 MULTIPROCESS_IPC_TEST_CLIENT_MAIN(SendFdsSandboxedClient) {
 182   struct stat st;
 183   const int fd = open(kDevZeroPath, O_RDONLY);
 184   fstat(fd, &st);
 185   if (IGNORE_EINTR(close(fd)) < 0)
 186     return -1;
 187
 188   // Enable the sandbox.
 189   char* error_buff = NULL;
 190   int error = sandbox_init(kSBXProfilePureComputation, SANDBOX_NAMED,
 191                            &error_buff);
 192   bool success = (error == 0 && error_buff == NULL);
 193   if (!success)
 194     return -1;
 195
 196   sandbox_free_error(error_buff);
 197
 198   // Make sure sandbox is really enabled.
 199   if (open(kDevZeroPath, O_RDONLY) != -1) {
 200     LOG(ERROR) << "Sandbox wasn't properly enabled";
 201     return -1;
 202   }
 203
 204   // See if we can receive a file descriptor.
 205   return SendFdsClientCommon("SendFdsSandboxedClient", st.st_ino);
 206 }
 207 #endif  // defined(OS_MACOSX)
 208
 209
 210 class MyCBListener : public MyChannelDescriptorListenerBase {
 211  public:
 212   MyCBListener(base::Callback<void(int)> cb, int fds_to_send)
 213       : MyChannelDescriptorListenerBase(),
 214         cb_(cb) {
 215     }
 216
 217  protected:
 218   void HandleFD(int fd) override { cb_.Run(fd); }
 219  private:
 220   base::Callback<void(int)> cb_;
 221 };
 222
 223 std::pair<int, int> make_socket_pair() {
 224   int pipe_fds[2];
 225   CHECK_EQ(0, HANDLE_EINTR(socketpair(AF_UNIX, SOCK_STREAM, 0, pipe_fds)));
 226   return std::pair<int, int>(pipe_fds[0], pipe_fds[1]);
 227 }
 228
 229 static void null_cb(int unused_fd) {
 230   NOTREACHED();
 231 }
 232
 233 class PipeChannelHelper {
 234  public:
 235   PipeChannelHelper(base::Thread* in_thread,
 236                     base::Thread* out_thread,
 237                     base::Callback<void(int)> cb,
 238                     int fds_to_send) :
 239       in_thread_(in_thread),
 240       out_thread_(out_thread),
 241       cb_listener_(cb, fds_to_send),
 242       null_listener_(base::Bind(&null_cb), 0) {
 243   }
 244
 245   void Init() {
 246     IPC::ChannelHandle in_handle("IN");
 247     in = IPC::Channel::CreateServer(in_handle, &null_listener_, nullptr);
 248     IPC::ChannelHandle out_handle(
 249         "OUT", base::FileDescriptor(in->TakeClientFileDescriptor()));
 250     out = IPC::Channel::CreateClient(out_handle, &cb_listener_, nullptr);
 251     // PostTask the connect calls to make sure the callbacks happens
 252     // on the right threads.
 253     in_thread_->task_runner()->PostTask(
 254         FROM_HERE, base::Bind(&PipeChannelHelper::Connect, in.get()));
 255     out_thread_->task_runner()->PostTask(
 256         FROM_HERE, base::Bind(&PipeChannelHelper::Connect, out.get()));
 257   }
 258
 259   static void DestroyChannel(scoped_ptr<IPC::Channel> *c,
 260                              base::WaitableEvent *event) {
 261     c->reset(0);
 262     event->Signal();
 263   }
 264
 265   ~PipeChannelHelper() {
 266     base::WaitableEvent a(true, false);
 267     base::WaitableEvent b(true, false);
 268     in_thread_->task_runner()->PostTask(
 269         FROM_HERE, base::Bind(&PipeChannelHelper::DestroyChannel, &in, &a));
 270     out_thread_->task_runner()->PostTask(
 271         FROM_HERE, base::Bind(&PipeChannelHelper::DestroyChannel, &out, &b));
 272     a.Wait();
 273     b.Wait();
 274   }
 275
 276   static void Connect(IPC::Channel *channel) {
 277     EXPECT_TRUE(channel->Connect());
 278   }
 279
 280   void Send(int fd) {
 281     CHECK_EQ(base::MessageLoop::current(), in_thread_->message_loop());
 282
 283     ASSERT_GE(fd, 0);
 284     base::FileDescriptor descriptor(fd, true);
 285
 286     IPC::Message* message =
 287         new IPC::Message(0, 3, IPC::Message::PRIORITY_NORMAL);
 288     IPC::ParamTraits<base::FileDescriptor>::Write(message, descriptor);
 289     ASSERT_TRUE(in->Send(message));
 290   }
 291
 292  private:
 293   scoped_ptr<IPC::Channel> in, out;
 294   base::Thread* in_thread_;
 295   base::Thread* out_thread_;
 296   MyCBListener cb_listener_;
 297   MyCBListener null_listener_;
 298 };
 299
 300 // This test is meant to provoke a kernel bug on OSX, and to prove
 301 // that the workaround for it is working. It sets up two pipes and three
 302 // threads, the producer thread creates socketpairs and sends one of the fds
 303 // over pipe1 to the middleman thread. The middleman thread simply takes the fd
 304 // sends it over pipe2 to the consumer thread. The consumer thread writes a byte
 305 // to each fd it receives and then closes the pipe. The producer thread reads
 306 // the bytes back from each pair of pipes and make sure that everything worked.
 307 // This feedback mechanism makes sure that not too many file descriptors are
 308 // in flight at the same time. For more info on the bug, see:
 309 // http://crbug.com/298276
 310 class IPCMultiSendingFdsTest : public testing::Test {
 311  public:
 312   IPCMultiSendingFdsTest() : received_(true, false) {}
 313
 314   void Producer(PipeChannelHelper* dest,
 315                 base::Thread* t,
 316                 int pipes_to_send) {
 317     for (int i = 0; i < pipes_to_send; i++) {
 318       received_.Reset();
 319       std::pair<int, int> pipe_fds = make_socket_pair();
 320       t->task_runner()->PostTask(
 321           FROM_HERE, base::Bind(&PipeChannelHelper::Send,
 322                                 base::Unretained(dest), pipe_fds.second));
 323       char tmp = 'x';
 324       CHECK_EQ(1, HANDLE_EINTR(write(pipe_fds.first, &tmp, 1)));
 325       CHECK_EQ(0, IGNORE_EINTR(close(pipe_fds.first)));
 326       received_.Wait();
 327     }
 328   }
 329
 330   void ConsumerHandleFD(int fd) {
 331     char tmp = 'y';
 332     CHECK_EQ(1, HANDLE_EINTR(read(fd, &tmp, 1)));
 333     CHECK_EQ(tmp, 'x');
 334     CHECK_EQ(0, IGNORE_EINTR(close(fd)));
 335     received_.Signal();
 336   }
 337
 338   base::Thread* CreateThread(const char* name) {
 339     base::Thread* ret = new base::Thread(name);
 340     base::Thread::Options options;
 341     options.message_loop_type = base::MessageLoop::TYPE_IO;
 342     ret->StartWithOptions(options);
 343     return ret;
 344   }
 345
 346   void Run() {
 347     // On my mac, this test fails roughly 35 times per
 348     // million sends with low load, but much more with high load.
 349     // Unless the workaround is in place. With 10000 sends, we
 350     // should see at least a 3% failure rate.
 351     const int pipes_to_send = 20000;
 352     scoped_ptr<base::Thread> producer(CreateThread("producer"));
 353     scoped_ptr<base::Thread> middleman(CreateThread("middleman"));
 354     scoped_ptr<base::Thread> consumer(CreateThread("consumer"));
 355     PipeChannelHelper pipe1(
 356         middleman.get(),
 357         consumer.get(),
 358         base::Bind(&IPCMultiSendingFdsTest::ConsumerHandleFD,
 359                    base::Unretained(this)),
 360         pipes_to_send);
 361     PipeChannelHelper pipe2(
 362         producer.get(),
 363         middleman.get(),
 364         base::Bind(&PipeChannelHelper::Send, base::Unretained(&pipe1)),
 365         pipes_to_send);
 366     pipe1.Init();
 367     pipe2.Init();
 368     Producer(&pipe2, producer.get(), pipes_to_send);
 369   }
 370
 371  private:
 372   base::WaitableEvent received_;
 373 };
 374
 375 TEST_F(IPCMultiSendingFdsTest, StressTest) {
 376   Run();
 377 }
 378
 379 }  // namespace
 380
 381 #endif  // defined(OS_POSIX)