[net] Adds AddressTrackerLinux which keeps track of interface addresses using rtnetlink.

net/base/network_change_notifier_linux.cc

 // Copyright (c) 2012 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.
 //
 // This implementation of NetworkChangeNotifier's offline state detection
 // depends on D-Bus and NetworkManager, and is known to work on at least
 // GNOME version 2.30.  If D-Bus or NetworkManager are unavailable, this
 // implementation will always behave as if it is online.
 
 #include "net/base/network_change_notifier_linux.h"
 
-#include <errno.h>
 #include <resolv.h>
-#include <sys/socket.h>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/callback.h"
 #include "base/compiler_specific.h"
-#include "base/eintr_wrapper.h"
 #include "base/memory/weak_ptr.h"
 #include "base/synchronization/lock.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/threading/platform_thread.h"
 #include "base/threading/thread.h"
 #include "base/threading/thread_restrictions.h"
 #include "dbus/bus.h"
 #include "dbus/message.h"
 #include "dbus/object_proxy.h"
+#include "net/base/address_tracker_linux.h"
 #include "net/base/net_errors.h"
-#include "net/base/network_change_notifier_netlink_linux.h"
 #include "net/dns/dns_config_watcher.h"
 
 namespace net {
 
 namespace {
 
-const int kInvalidSocket = -1;
-
 const char kNetworkManagerServiceName[] = "org.freedesktop.NetworkManager";
 const char kNetworkManagerPath[] = "/org/freedesktop/NetworkManager";
 const char kNetworkManagerInterface[] = "org.freedesktop.NetworkManager";
 
 // http://projects.gnome.org/NetworkManager/developers/spec-08.html#type-NM_STATE
 enum {
   NM_LEGACY_STATE_UNKNOWN = 0,
   NM_LEGACY_STATE_ASLEEP = 1,
   NM_LEGACY_STATE_CONNECTING = 2,
   NM_LEGACY_STATE_CONNECTED = 3,
@@ skipping 186 matching lines @@
 NetworkManagerApi::GetCurrentConnectionType() {
   // http://crbug.com/125097
   base::ThreadRestrictions::ScopedAllowWait allow_wait;
   offline_state_initialized_.Wait();
   base::AutoLock lock(is_offline_lock_);
   // TODO(droger): Return something more detailed than CONNECTION_UNKNOWN.
   return is_offline_ ? NetworkChangeNotifier::CONNECTION_NONE :
                        NetworkChangeNotifier::CONNECTION_UNKNOWN;
 }
 
-class NetworkChangeNotifierLinux::Thread
-    : public base::Thread, public MessageLoopForIO::Watcher {
+class NetworkChangeNotifierLinux::Thread : public base::Thread {
  public:
   explicit Thread(dbus::Bus* bus);
   virtual ~Thread();
 
-  // MessageLoopForIO::Watcher:
-  virtual void OnFileCanReadWithoutBlocking(int fd) OVERRIDE;
-  virtual void OnFileCanWriteWithoutBlocking(int /* fd */) OVERRIDE;
-
   // Plumbing for NetworkChangeNotifier::GetCurrentConnectionType.
   // Safe to call from any thread.
   NetworkChangeNotifier::ConnectionType GetCurrentConnectionType() {
     return network_manager_api_.GetCurrentConnectionType();
   }
 
+  const internal::AddressTrackerLinux* address_tracker() const {
+    return &address_tracker_;
+  }
+
  protected:
   // base::Thread
   virtual void Init() OVERRIDE;
   virtual void CleanUp() OVERRIDE;
 
  private:
-  // 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_;
-
   // Used to detect online/offline state changes.
   NetworkManagerApi network_manager_api_;
 
   internal::DnsConfigWatcher dns_watcher_;
+  internal::AddressTrackerLinux address_tracker_;
 
   DISALLOW_COPY_AND_ASSIGN(Thread);
 };
 
 NetworkChangeNotifierLinux::Thread::Thread(dbus::Bus* bus)
     : base::Thread("NetworkChangeNotifier"),
-      netlink_fd_(kInvalidSocket),
       network_manager_api_(
           base::Bind(&NetworkChangeNotifier::
                      NotifyObserversOfConnectionTypeChange),
-          bus) {
+          bus),
+      address_tracker_(
+          base::Bind(&NetworkChangeNotifier::
+                     NotifyObserversOfIPAddressChange)) {
 }
 
 NetworkChangeNotifierLinux::Thread::~Thread() {
   DCHECK(!Thread::IsRunning());
 }
 
 void NetworkChangeNotifierLinux::Thread::Init() {
-  netlink_fd_ = InitializeNetlinkSocket();
-  if (netlink_fd_ < 0) {
-    netlink_fd_ = kInvalidSocket;
-    return;
-  }
-  ListenForNotifications();
-
   network_manager_api_.Init();
-
   dns_watcher_.Init();
+  address_tracker_.Init();
 }
 
 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();
-  }
   network_manager_api_.CleanUp();
-
   dns_watcher_.CleanUp();
 }
 
-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.";
-      NotifyObserversOfIPAddressChange();
-    }
-    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, len);
-  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::Create() {
   return new NetworkChangeNotifierLinux(NULL);
 }
 
 NetworkChangeNotifierLinux* NetworkChangeNotifierLinux::CreateForTest(
     dbus::Bus* bus) {
   return new NetworkChangeNotifierLinux(bus);
 }
 
 NetworkChangeNotifierLinux::NetworkChangeNotifierLinux(dbus::Bus* bus)
     : notifier_thread_(new Thread(bus)) {
   // 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() {
   // Stopping from here allows us to sanity- check that the notifier
   // thread shut down properly.
   notifier_thread_->Stop();
 }
 
 NetworkChangeNotifier::ConnectionType
 NetworkChangeNotifierLinux::GetCurrentConnectionType() const {
   return notifier_thread_->GetCurrentConnectionType();
 }
 
+const internal::AddressTrackerLinux*
+NetworkChangeNotifierLinux::GetAddressTrackerInternal() const {
+  return notifier_thread_->address_tracker();
+}
+
 }  // namespace net