Bluetooth: Profile support for Chrome OS

device/bluetooth/bluetooth_socket_experimental_chromeos.cc

+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "device/bluetooth/bluetooth_socket_experimental_chromeos.h"
+
+#include <errno.h>
+#include <poll.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include <string>
+
+#include "base/logging.h"
+#include "base/memory/ref_counted.h"
+#include "base/posix/eintr_wrapper.h"
+#include "base/safe_strerror_posix.h"
+#include "base/threading/thread_restrictions.h"
+#include "dbus/file_descriptor.h"
+#include "device/bluetooth/bluetooth_socket.h"
+#include "net/base/io_buffer.h"
+
+namespace chromeos {
+
+BluetoothSocketExperimentalChromeOS::BluetoothSocketExperimentalChromeOS(
+    int fd)
+    : fd_(fd) {
+  // Fetch the socket type so we read from it correctly.
+  int optval;
+  socklen_t opt_len = sizeof optval;
+  if (getsockopt(fd_, SOL_SOCKET, SO_TYPE, &optval, &opt_len) < 0) {
+    // Sequenced packet is the safest assumption since it won't result in
+    // truncated packets.
+    LOG(WARNING) << "Unable to get socket type: " << safe_strerror(errno);
+    optval = SOCK_SEQPACKET;
+  }
+
+  if (optval == SOCK_DGRAM || optval == SOCK_SEQPACKET) {
+    socket_type_ = L2CAP;
+  } else {
+    socket_type_ = RFCOMM;
+  }
+}
+
+BluetoothSocketExperimentalChromeOS::~BluetoothSocketExperimentalChromeOS() {
+  HANDLE_EINTR(close(fd_));
+}
+
+bool BluetoothSocketExperimentalChromeOS::Receive(
+    net::GrowableIOBuffer *buffer) {
+  base::ThreadRestrictions::AssertIOAllowed();
+
+  if (socket_type_ == L2CAP) {
+    int count;
+    if (ioctl(fd_, FIONREAD, &count) < 0) {
+      error_message_ = safe_strerror(errno);
+      LOG(WARNING) << "Unable to get waiting data size: " << error_message_;
+      return true;
+    }
+
+    // No bytes waiting can mean either nothing to read, or the other end has
+    // been closed, and reading zero bytes always returns zero.
+    //
+    // We can't do a short read for fear of a race where data arrives between
+    // calls and we trunctate it. So use poll() to check for the POLLHUP flag.
+    if (count == 0) {
+      struct pollfd pollfd;
+
+      pollfd.fd = fd_;
+      pollfd.events = 0;
+      pollfd.revents = 0;
+
+      if (HANDLE_EINTR(poll(&pollfd, 1, 0)) < 0) {

[satorux1, 2013/05/07 08:07:16]

I need to check the manual to confirm that this won't block. Maybe add something
like

// Timeout parameter set to 0 so it won't block.

+        error_message_ = safe_strerror(errno);
+        LOG(WARNING) << "Unable to check whether socket is closed: "
+                     << error_message_;
+        return false;
+      }
+
+      if (pollfd.revents & POLLHUP) {
+        // TODO(keybuk, youngki): Agree a common way to flag disconnected.
+        error_message_ = "Disconnected";
+        return false;
+      }
+    }
+
+    buffer->SetCapacity(count);
+  } else {
+    buffer->SetCapacity(1024);
+  }
+
+  ssize_t bytes_read;
+  do {
+    if (buffer->RemainingCapacity() == 0)
+      buffer->SetCapacity(buffer->capacity() * 2);
+    bytes_read =
+        HANDLE_EINTR(read(fd_, buffer->data(), buffer->RemainingCapacity()));
+    if (bytes_read > 0)
+      buffer->set_offset(buffer->offset() + bytes_read);
+  } while (socket_type_ == RFCOMM && bytes_read > 0);
+
+  // Ignore an error if at least one read() call succeeded; it'll be returned
+  // the next read() call.
+  if (buffer->offset() > 0)
+    return true;
+
+  if (bytes_read < 0) {
+    if (errno == ECONNRESET || errno == ENOTCONN) {
+      // TODO(keybuk, youngki): Agree a common way to flag disconnected.
+      error_message_ = "Disconnected";
+      return false;
+    } else if (errno != EAGAIN && errno != EWOULDBLOCK) {
+      error_message_ = safe_strerror(errno);
+      return false;
+    }
+  }
+
+  if (bytes_read == 0 && socket_type_ == RFCOMM) {
+    // TODO(keybuk, youngki): Agree a common way to flag disconnected.
+    error_message_ = "Disconnected";
+    return false;
+  }
+
+  return true;
+}
+
+bool BluetoothSocketExperimentalChromeOS::Send(
+    net::DrainableIOBuffer *buffer) {
+  base::ThreadRestrictions::AssertIOAllowed();
+
+  ssize_t bytes_written;
+  do {
+    bytes_written =
+        HANDLE_EINTR(write(fd_, buffer->data(), buffer->BytesRemaining()));
+    if (bytes_written > 0)
+      buffer->DidConsume(bytes_written);
+  } while (buffer->BytesRemaining() > 0 && bytes_written > 0);
+
+  if (bytes_written < 0) {
+    if (errno == EPIPE || errno == ECONNRESET || errno == ENOTCONN) {
+      // TODO(keybuk, youngki): Agree a common way to flag disconnected.
+      error_message_ = "Disconnected";
+      return false;
+    } else if (errno != EAGAIN && errno != EWOULDBLOCK) {
+      error_message_ = safe_strerror(errno);
+      return false;
+    }
+  }
+
+  return true;
+}
+
+std::string BluetoothSocketExperimentalChromeOS::GetLastErrorMessage() const {
+  return error_message_;
+}
+
+// static
+scoped_refptr<device::BluetoothSocket>
+BluetoothSocketExperimentalChromeOS::Create(dbus::FileDescriptor* fd) {
+  DCHECK(fd->is_valid());
+
+  BluetoothSocketExperimentalChromeOS* bluetooth_socket =
+      new BluetoothSocketExperimentalChromeOS(fd->TakeValue());;
+  return scoped_refptr<BluetoothSocketExperimentalChromeOS>(bluetooth_socket);
+}
+
+}  // namespace chromeos