device/bluetooth/bluetooth_socket_chromeos.cc

   1 // Copyright 2013 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 "device/bluetooth/bluetooth_socket_chromeos.h"
   6
   7 #include <errno.h>
   8 #include <poll.h>
   9 #include <unistd.h>
  10 #include <sys/ioctl.h>
  11 #include <sys/types.h>
  12 #include <sys/socket.h>
  13
  14 #include <string>
  15
  16 #include "base/logging.h"
  17 #include "base/memory/ref_counted.h"
  18 #include "base/posix/eintr_wrapper.h"
  19 #include "base/safe_strerror_posix.h"
  20 #include "base/threading/thread_restrictions.h"
  21 #include "dbus/file_descriptor.h"
  22 #include "device/bluetooth/bluetooth_socket.h"
  23 #include "net/base/io_buffer.h"
  24
  25 namespace chromeos {
  26
  27 BluetoothSocketChromeOS::BluetoothSocketChromeOS(int fd)
  28     : fd_(fd) {
  29   // Fetch the socket type so we read from it correctly.
  30   int optval;
  31   socklen_t opt_len = sizeof optval;
  32   if (getsockopt(fd_, SOL_SOCKET, SO_TYPE, &optval, &opt_len) < 0) {
  33     // Sequenced packet is the safest assumption since it won't result in
  34     // truncated packets.
  35     LOG(WARNING) << "Unable to get socket type: " << safe_strerror(errno);
  36     optval = SOCK_SEQPACKET;
  37   }
  38
  39   if (optval == SOCK_DGRAM || optval == SOCK_SEQPACKET) {
  40     socket_type_ = L2CAP;
  41   } else {
  42     socket_type_ = RFCOMM;
  43   }
  44 }
  45
  46 BluetoothSocketChromeOS::~BluetoothSocketChromeOS() {
  47   HANDLE_EINTR(close(fd_));
  48 }
  49
  50 bool BluetoothSocketChromeOS::Receive(net::GrowableIOBuffer *buffer) {
  51   base::ThreadRestrictions::AssertIOAllowed();
  52
  53   if (socket_type_ == L2CAP) {
  54     int count;
  55     if (ioctl(fd_, FIONREAD, &count) < 0) {
  56       error_message_ = safe_strerror(errno);
  57       LOG(WARNING) << "Unable to get waiting data size: " << error_message_;
  58       return true;
  59     }
  60
  61     // No bytes waiting can mean either nothing to read, or the other end has
  62     // been closed, and reading zero bytes always returns zero.
  63     //
  64     // We can't do a short read for fear of a race where data arrives between
  65     // calls and we trunctate it. So use poll() to check for the POLLHUP flag.
  66     if (count == 0) {
  67       struct pollfd pollfd;
  68
  69       pollfd.fd = fd_;
  70       pollfd.events = 0;
  71       pollfd.revents = 0;
  72
  73       // Timeout parameter set to 0 so this call will not block.
  74       if (HANDLE_EINTR(poll(&pollfd, 1, 0)) < 0) {
  75         error_message_ = safe_strerror(errno);
  76         LOG(WARNING) << "Unable to check whether socket is closed: "
  77                      << error_message_;
  78         return false;
  79       }
  80
  81       if (pollfd.revents & POLLHUP) {
  82         // TODO(keybuk, youngki): Agree a common way to flag disconnected.
  83         error_message_ = "Disconnected";
  84         return false;
  85       }
  86     }
  87
  88     buffer->SetCapacity(count);
  89   } else {
  90     buffer->SetCapacity(1024);
  91   }
  92
  93   ssize_t bytes_read;
  94   do {
  95     if (buffer->RemainingCapacity() == 0)
  96       buffer->SetCapacity(buffer->capacity() * 2);
  97     bytes_read =
  98         HANDLE_EINTR(read(fd_, buffer->data(), buffer->RemainingCapacity()));
  99     if (bytes_read > 0)
 100       buffer->set_offset(buffer->offset() + bytes_read);
 101   } while (socket_type_ == RFCOMM && bytes_read > 0);
 102
 103   // Ignore an error if at least one read() call succeeded; it'll be returned
 104   // the next read() call.
 105   if (buffer->offset() > 0)
 106     return true;
 107
 108   if (bytes_read < 0) {
 109     if (errno == ECONNRESET || errno == ENOTCONN) {
 110       // TODO(keybuk, youngki): Agree a common way to flag disconnected.
 111       error_message_ = "Disconnected";
 112       return false;
 113     } else if (errno != EAGAIN && errno != EWOULDBLOCK) {
 114       error_message_ = safe_strerror(errno);
 115       return false;
 116     }
 117   }
 118
 119   if (bytes_read == 0 && socket_type_ == RFCOMM) {
 120     // TODO(keybuk, youngki): Agree a common way to flag disconnected.
 121     error_message_ = "Disconnected";
 122     return false;
 123   }
 124
 125   return true;
 126 }
 127
 128 bool BluetoothSocketChromeOS::Send(net::DrainableIOBuffer *buffer) {
 129   base::ThreadRestrictions::AssertIOAllowed();
 130
 131   ssize_t bytes_written;
 132   do {
 133     bytes_written =
 134         HANDLE_EINTR(write(fd_, buffer->data(), buffer->BytesRemaining()));
 135     if (bytes_written > 0)
 136       buffer->DidConsume(bytes_written);
 137   } while (buffer->BytesRemaining() > 0 && bytes_written > 0);
 138
 139   if (bytes_written < 0) {
 140     if (errno == EPIPE || errno == ECONNRESET || errno == ENOTCONN) {
 141       // TODO(keybuk, youngki): Agree a common way to flag disconnected.
 142       error_message_ = "Disconnected";
 143       return false;
 144     } else if (errno != EAGAIN && errno != EWOULDBLOCK) {
 145       error_message_ = safe_strerror(errno);
 146       return false;
 147     }
 148   }
 149
 150   return true;
 151 }
 152
 153 std::string BluetoothSocketChromeOS::GetLastErrorMessage() const {
 154   return error_message_;
 155 }
 156
 157 // static
 158 scoped_refptr<device::BluetoothSocket> BluetoothSocketChromeOS::Create(
 159     dbus::FileDescriptor* fd) {
 160   DCHECK(fd->is_valid());
 161
 162   BluetoothSocketChromeOS* bluetooth_socket =
 163       new BluetoothSocketChromeOS(fd->TakeValue());;
 164   return scoped_refptr<BluetoothSocketChromeOS>(bluetooth_socket);
 165 }
 166
 167 }  // namespace chromeos