Move ScopedFileDescriptor to dbus/file_descriptor.h

ScopedFileDescriptor was initially introduced to facilitate the
management of a 'lifeline' FD used when asking permission_broker to
open a port in the device's firewall on CrOS.  It's actually a scoped
wrapper around DBus::FileDescriptor, not a platform file descriptor. I
would like to use it to facilitate some other similar functionality in
which I create a pipe and pass one end over DBus, so it seems like a
good idea to move ScopedFileDescriptor into the dbus library directly.

BUG=chromium:481340
TEST=FirewallHole unit tests still pass
STATUS=Fixed
R=keybuk, reillyg, stevenjb

Review URL: https://codereview.chromium.org/1090243003

Cr-Commit-Position: refs/heads/master@{#327089}

chromeos/network/firewall_hole.cc

@@ -50,7 +50,7 @@ const char* PortTypeToString(FirewallHole::PortType type) {
 void PortReleased(FirewallHole::PortType type,
                   uint16_t port,
                   const std::string& interface,
-                  FirewallHole::ScopedFileDescriptor lifeline_fd,
+                  dbus::ScopedFileDescriptor lifeline_fd,
                   bool success) {
   if (!success) {
     LOG(WARNING) << "Failed to release firewall hole for "
@@ -61,20 +61,13 @@ void PortReleased(FirewallHole::PortType type,
 
 }  // namespace
 
-void CHROMEOS_EXPORT FirewallHole::FileDescriptorDeleter::operator()(
-    dbus::FileDescriptor* fd) {
-  base::WorkerPool::PostTask(
-      FROM_HERE, base::Bind(&base::DeletePointer<dbus::FileDescriptor>, fd),
-      false);
-}
-
 // static
 void FirewallHole::Open(PortType type,
                         uint16_t port,
                         const std::string& interface,
                         const OpenCallback& callback) {
-  ScopedFileDescriptor lifeline_local(new dbus::FileDescriptor());
-  ScopedFileDescriptor lifeline_remote(new dbus::FileDescriptor());
+  dbus::ScopedFileDescriptor lifeline_local(new dbus::FileDescriptor());
+  dbus::ScopedFileDescriptor lifeline_remote(new dbus::FileDescriptor());
 
   // This closure shares pointers with the one below. PostTaskAndReply
   // guarantees that it will always be deleted first.
@@ -109,8 +102,8 @@ FirewallHole::~FirewallHole() {
 void FirewallHole::RequestPortAccess(PortType type,
                                      uint16_t port,
                                      const std::string& interface,
-                                     ScopedFileDescriptor lifeline_local,
-                                     ScopedFileDescriptor lifeline_remote,
+                                     dbus::ScopedFileDescriptor lifeline_local,
+                                     dbus::ScopedFileDescriptor lifeline_remote,
                                      const OpenCallback& callback) {
   if (!lifeline_local->is_valid() || !lifeline_remote->is_valid()) {
     callback.Run(nullptr);
@@ -140,7 +133,7 @@ void FirewallHole::RequestPortAccess(PortType type,
 void FirewallHole::PortAccessGranted(PortType type,
                                      uint16_t port,
                                      const std::string& interface,
-                                     ScopedFileDescriptor lifeline_fd,
+                                     dbus::ScopedFileDescriptor lifeline_fd,
                                      const FirewallHole::OpenCallback& callback,
                                      bool success) {
   if (success) {
@@ -154,7 +147,7 @@ void FirewallHole::PortAccessGranted(PortType type,
 FirewallHole::FirewallHole(PortType type,
                            uint16_t port,
                            const std::string& interface,
-                           ScopedFileDescriptor lifeline_fd)
+                           dbus::ScopedFileDescriptor lifeline_fd)
     : type_(type),
       port_(port),
       interface_(interface),

chromeos/network/firewall_hole.h

@@ -11,10 +11,7 @@
 #include "base/callback_forward.h"
 #include "base/memory/scoped_ptr.h"
 #include "chromeos/chromeos_export.h"
-
-namespace dbus {
-class FileDescriptor;
-}
+#include "dbus/file_descriptor.h"
 
 namespace chromeos {
 
@@ -29,14 +26,6 @@ class CHROMEOS_EXPORT FirewallHole {
 
   typedef base::Callback<void(scoped_ptr<FirewallHole>)> OpenCallback;
 
-  // This provides a simple way to pass around file descriptors since they must
-  // be closed on a thread that is allowed to perform I/O.
-  struct FileDescriptorDeleter {
-    void CHROMEOS_EXPORT operator()(dbus::FileDescriptor* fd);
-  };
-  typedef scoped_ptr<dbus::FileDescriptor, FileDescriptorDeleter>
-      ScopedFileDescriptor;
-
   // Opens a port on the system firewall for the given network interface (or all
   // interfaces if |interface| is ""). The hole will be closed when the object
   // provided to the callback is destroyed.
@@ -51,28 +40,28 @@ class CHROMEOS_EXPORT FirewallHole {
   static void RequestPortAccess(PortType type,
                                 uint16_t port,
                                 const std::string& interface,
-                                ScopedFileDescriptor lifeline_local,
-                                ScopedFileDescriptor lifeline_remote,
+                                dbus::ScopedFileDescriptor lifeline_local,
+                                dbus::ScopedFileDescriptor lifeline_remote,
                                 const OpenCallback& callback);
 
   static void PortAccessGranted(PortType type,
                                 uint16_t port,
                                 const std::string& interface,
-                                ScopedFileDescriptor lifeline_fd,
+                                dbus::ScopedFileDescriptor lifeline_fd,
                                 const FirewallHole::OpenCallback& callback,
                                 bool success);
 
   FirewallHole(PortType type,
                uint16_t port,
                const std::string& interface,
-               ScopedFileDescriptor lifeline_fd);
+               dbus::ScopedFileDescriptor lifeline_fd);
 
   const PortType type_;
   const uint16_t port_;
   const std::string interface_;
 
   // A file descriptor used by firewalld to track the lifetime of this process.
-  ScopedFileDescriptor lifeline_fd_;
+  dbus::ScopedFileDescriptor lifeline_fd_;
 };
 
 }  // namespace chromeos

dbus/file_descriptor.cc

@@ -2,12 +2,21 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "base/bind.h"
 #include "base/files/file.h"
+#include "base/location.h"
 #include "base/logging.h"
+#include "base/threading/worker_pool.h"
 #include "dbus/file_descriptor.h"
 
 namespace dbus {
 
+void CHROME_DBUS_EXPORT FileDescriptor::Deleter::operator()(
+    FileDescriptor* fd) {
+  base::WorkerPool::PostTask(
+      FROM_HERE, base::Bind(&base::DeletePointer<FileDescriptor>, fd), false);
+}
+
 FileDescriptor::~FileDescriptor() {
   if (owner_)
     base::File auto_closer(value_);

dbus/file_descriptor.h

@@ -6,6 +6,7 @@
 #define DBUS_FILE_DESCRIPTOR_H_
 
 #include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
 #include "dbus/dbus_export.h"
 
 namespace dbus {
@@ -33,6 +34,12 @@ namespace dbus {
 // with i/o restrictions.
 class CHROME_DBUS_EXPORT FileDescriptor {
  public:
+  // This provides a simple way to pass around file descriptors since they must
+  // be closed on a thread that is allowed to perform I/O.
+  struct Deleter {
+    void CHROME_DBUS_EXPORT operator()(FileDescriptor* fd);
+  };
+
   // Permits initialization without a value for passing to
   // dbus::MessageReader::PopFileDescriptor to fill in and from int values.
   FileDescriptor() : value_(-1), owner_(false), valid_(false) {}
@@ -70,6 +77,9 @@ class CHROME_DBUS_EXPORT FileDescriptor {
   DISALLOW_COPY_AND_ASSIGN(FileDescriptor);
 };
 
+using ScopedFileDescriptor =
+    scoped_ptr<FileDescriptor, FileDescriptor::Deleter> CHROME_DBUS_EXPORT;
+
 }  // namespace dbus
 
 #endif  // DBUS_FILE_DESCRIPTOR_H_