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