ipc/glue/FileDescriptor.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "FileDescriptor.h"
   8
   9 #include "mozilla/Assertions.h"
  10 #include "mozilla/ipc/IPDLParamTraits.h"
  11 #include "mozilla/ipc/ProtocolMessageUtils.h"
  12 #include "nsDebug.h"
  13
  14 #ifdef XP_WIN
  15 #  include <windows.h>
  16 #  include "ProtocolUtils.h"
  17 #else  // XP_WIN
  18 #  include <unistd.h>
  19 #endif  // XP_WIN
  20
  21 namespace mozilla {
  22 namespace ipc {
  23
  24 FileDescriptor::FileDescriptor() = default;
  25
  26 FileDescriptor::FileDescriptor(const FileDescriptor& aOther)
  27     : mHandle(Clone(aOther.mHandle.get())) {}
  28
  29 FileDescriptor::FileDescriptor(FileDescriptor&& aOther)
  30     : mHandle(std::move(aOther.mHandle)) {}
  31
  32 FileDescriptor::FileDescriptor(PlatformHandleType aHandle)
  33     : mHandle(Clone(aHandle)) {}
  34
  35 FileDescriptor::FileDescriptor(UniquePlatformHandle&& aHandle)
  36     : mHandle(std::move(aHandle)) {}
  37
  38 FileDescriptor::~FileDescriptor() = default;
  39
  40 FileDescriptor& FileDescriptor::operator=(const FileDescriptor& aOther) {
  41   if (this != &aOther) {
  42     mHandle = Clone(aOther.mHandle.get());
  43   }
  44   return *this;
  45 }
  46
  47 FileDescriptor& FileDescriptor::operator=(FileDescriptor&& aOther) {
  48   if (this != &aOther) {
  49     mHandle = std::move(aOther.mHandle);
  50   }
  51   return *this;
  52 }
  53
  54 bool FileDescriptor::IsValid() const { return mHandle != nullptr; }
  55
  56 FileDescriptor::UniquePlatformHandle FileDescriptor::ClonePlatformHandle()
  57     const {
  58   return Clone(mHandle.get());
  59 }
  60
  61 FileDescriptor::UniquePlatformHandle FileDescriptor::TakePlatformHandle() {
  62   return UniquePlatformHandle(mHandle.release());
  63 }
  64
  65 bool FileDescriptor::operator==(const FileDescriptor& aOther) const {
  66   return mHandle == aOther.mHandle;
  67 }
  68
  69 // static
  70 FileDescriptor::UniquePlatformHandle FileDescriptor::Clone(
  71     PlatformHandleType aHandle) {
  72   FileDescriptor::PlatformHandleType newHandle;
  73
  74 #ifdef XP_WIN
  75   if (aHandle == INVALID_HANDLE_VALUE || aHandle == nullptr) {
  76     return UniqueFileHandle();
  77   }
  78   if (::DuplicateHandle(GetCurrentProcess(), aHandle, GetCurrentProcess(),
  79                         &newHandle, 0, FALSE, DUPLICATE_SAME_ACCESS)) {
  80     return UniqueFileHandle(newHandle);
  81   }
  82 #else  // XP_WIN
  83   if (aHandle < 0) {
  84     return UniqueFileHandle();
  85   }
  86   newHandle = dup(aHandle);
  87   if (newHandle >= 0) {
  88     return UniqueFileHandle(newHandle);
  89   }
  90 #endif
  91   NS_WARNING("Failed to duplicate file handle for current process!");
  92   return UniqueFileHandle();
  93 }
  94
  95 void IPDLParamTraits<FileDescriptor>::Write(IPC::MessageWriter* aWriter,
  96                                             IProtocol* aActor,
  97                                             const FileDescriptor& aParam) {
  98   WriteIPDLParam(aWriter, aActor, aParam.ClonePlatformHandle());
  99 }
 100
 101 bool IPDLParamTraits<FileDescriptor>::Read(IPC::MessageReader* aReader,
 102                                            IProtocol* aActor,
 103                                            FileDescriptor* aResult) {
 104   UniqueFileHandle handle;
 105   if (!ReadIPDLParam(aReader, aActor, &handle)) {
 106     return false;
 107   }
 108
 109   *aResult = FileDescriptor(std::move(handle));
 110   if (!aResult->IsValid()) {
 111     printf_stderr("IPDL protocol Error: Received an invalid file descriptor\n");
 112   }
 113   return true;
 114 }
 115
 116 }  // namespace ipc
 117 }  // namespace mozilla