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// Copyright (c) 2010 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 "net/base/network_change_notifier_linux.h"
#include <errno.h>
#include <sys/socket.h>
#include "base/compiler_specific.h"
#include "base/eintr_wrapper.h"
#include "base/task.h"
#include "base/thread.h"
#include "net/base/net_errors.h"
#include "net/base/network_change_notifier_netlink_linux.h"
namespace net {
namespace {
const int kInvalidSocket = -1;
} // namespace
class NetworkChangeNotifierLinux::Thread
: public base::Thread, public MessageLoopForIO::Watcher {
public:
Thread();
virtual ~Thread();
// MessageLoopForIO::Watcher:
virtual void OnFileCanReadWithoutBlocking(int fd);
virtual void OnFileCanWriteWithoutBlocking(int /* fd */);
protected:
// base::Thread
virtual void Init();
virtual void CleanUp();
private:
void NotifyObserversOfIPAddressChange() {
NetworkChangeNotifier::NotifyObserversOfIPAddressChange();
}
// Starts listening for netlink messages. Also handles the messages if there
// are any available on the netlink socket.
void ListenForNotifications();
// Attempts to read from the netlink socket into |buf| of length |len|.
// Returns the bytes read on synchronous success and ERR_IO_PENDING if the
// recv() would block. Otherwise, it returns a net error code.
int ReadNotificationMessage(char* buf, size_t len);
// The netlink socket descriptor.
int netlink_fd_;
MessageLoopForIO::FileDescriptorWatcher netlink_watcher_;
// Technically only needed for ChromeOS, but it's ugly to #ifdef out.
ScopedRunnableMethodFactory<Thread> method_factory_;
DISALLOW_COPY_AND_ASSIGN(Thread);
};
NetworkChangeNotifierLinux::Thread::Thread()
: base::Thread("NetworkChangeNotifier"),
netlink_fd_(kInvalidSocket),
ALLOW_THIS_IN_INITIALIZER_LIST(method_factory_(this)) {}
NetworkChangeNotifierLinux::Thread::~Thread() {}
void NetworkChangeNotifierLinux::Thread::Init() {
netlink_fd_ = InitializeNetlinkSocket();
if (netlink_fd_ < 0) {
netlink_fd_ = kInvalidSocket;
return;
}
ListenForNotifications();
}
void NetworkChangeNotifierLinux::Thread::CleanUp() {
if (netlink_fd_ != kInvalidSocket) {
if (HANDLE_EINTR(close(netlink_fd_)) != 0)
PLOG(ERROR) << "Failed to close socket";
netlink_fd_ = kInvalidSocket;
netlink_watcher_.StopWatchingFileDescriptor();
}
}
void NetworkChangeNotifierLinux::Thread::OnFileCanReadWithoutBlocking(int fd) {
DCHECK_EQ(fd, netlink_fd_);
ListenForNotifications();
}
void NetworkChangeNotifierLinux::Thread::OnFileCanWriteWithoutBlocking(int /* fd */) {
NOTREACHED();
}
void NetworkChangeNotifierLinux::Thread::ListenForNotifications() {
char buf[4096];
int rv = ReadNotificationMessage(buf, arraysize(buf));
while (rv > 0) {
if (HandleNetlinkMessage(buf, rv)) {
VLOG(1) << "Detected IP address changes.";
#if defined(OS_CHROMEOS)
// TODO(oshima): chromium-os:8285 - introduced artificial delay to
// work around the issue of network load issue after connection
// restored. See the bug for more details.
// This should be removed once this bug is properly fixed.
const int kObserverNotificationDelayMS = 200;
message_loop()->PostDelayedTask(
FROM_HERE,
method_factory_.NewRunnableMethod(
&Thread::NotifyObserversOfIPAddressChange),
kObserverNotificationDelayMS);
#else
NotifyObserversOfIPAddressChange();
#endif
}
rv = ReadNotificationMessage(buf, arraysize(buf));
}
if (rv == ERR_IO_PENDING) {
rv = MessageLoopForIO::current()->WatchFileDescriptor(netlink_fd_, false,
MessageLoopForIO::WATCH_READ, &netlink_watcher_, this);
LOG_IF(ERROR, !rv) << "Failed to watch netlink socket: " << netlink_fd_;
}
}
int NetworkChangeNotifierLinux::Thread::ReadNotificationMessage(
char* buf,
size_t len) {
DCHECK_NE(len, 0u);
DCHECK(buf);
memset(buf, 0, sizeof(buf));
int rv = recv(netlink_fd_, buf, len, 0);
if (rv > 0)
return rv;
DCHECK_NE(rv, 0);
if (errno != EAGAIN && errno != EWOULDBLOCK) {
PLOG(DFATAL) << "recv";
return ERR_FAILED;
}
return ERR_IO_PENDING;
}
NetworkChangeNotifierLinux::NetworkChangeNotifierLinux()
: notifier_thread_(new Thread) {
// We create this notifier thread because the notification implementation
// needs a MessageLoopForIO, and there's no guarantee that
// MessageLoop::current() meets that criterion.
base::Thread::Options thread_options(MessageLoop::TYPE_IO, 0);
notifier_thread_->StartWithOptions(thread_options);
}
NetworkChangeNotifierLinux::~NetworkChangeNotifierLinux() {
// We don't need to explicitly Stop(), but doing so allows us to sanity-
// check that the notifier thread shut down properly.
notifier_thread_->Stop();
}
bool NetworkChangeNotifierLinux::IsCurrentlyOffline() const {
// TODO(eroman): http://crbug.com/53473
return false;
}
} // namespace net
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