ipc/glue/FileDescriptor.cpp

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #include "FileDescriptor.h"
   6
   7 #include "mozilla/Assertions.h"
   8 #include "nsDebug.h"
   9
  10 #ifdef XP_WIN
  11
  12 #include <windows.h>
  13 #define INVALID_HANDLE INVALID_HANDLE_VALUE
  14
  15 #else // XP_WIN
  16
  17 #include <unistd.h>
  18
  19 #ifndef OS_POSIX
  20 #define OS_POSIX
  21 #endif
  22
  23 #include "base/eintr_wrapper.h"
  24 #define INVALID_HANDLE -1
  25
  26 #endif // XP_WIN
  27
  28 using mozilla::ipc::FileDescriptor;
  29
  30 FileDescriptor::FileDescriptor()
  31 : mHandle(INVALID_HANDLE), mHandleCreatedByOtherProcess(false),
  32   mHandleCreatedByOtherProcessWasUsed(false)
  33 { }
  34
  35 FileDescriptor::FileDescriptor(PlatformHandleType aHandle)
  36 : mHandle(INVALID_HANDLE), mHandleCreatedByOtherProcess(false),
  37   mHandleCreatedByOtherProcessWasUsed(false)
  38 {
  39   DuplicateInCurrentProcess(aHandle);
  40 }
  41
  42 void
  43 FileDescriptor::DuplicateInCurrentProcess(PlatformHandleType aHandle)
  44 {
  45   MOZ_ASSERT_IF(mHandleCreatedByOtherProcess,
  46                 mHandleCreatedByOtherProcessWasUsed);
  47
  48   if (IsValid(aHandle)) {
  49     PlatformHandleType newHandle;
  50 #ifdef XP_WIN
  51     if (DuplicateHandle(GetCurrentProcess(), aHandle, GetCurrentProcess(),
  52                         &newHandle, 0, FALSE, DUPLICATE_SAME_ACCESS)) {
  53 #else // XP_WIN
  54     if ((newHandle = dup(aHandle)) != INVALID_HANDLE) {
  55 #endif
  56       mHandle = newHandle;
  57       return;
  58     }
  59     NS_WARNING("Failed to duplicate file handle for current process!");
  60   }
  61
  62   mHandle = INVALID_HANDLE;
  63 }
  64
  65 void
  66 FileDescriptor::CloseCurrentProcessHandle()
  67 {
  68   MOZ_ASSERT_IF(mHandleCreatedByOtherProcess,
  69                 mHandleCreatedByOtherProcessWasUsed);
  70
  71   // Don't actually close handles created by another process.
  72   if (mHandleCreatedByOtherProcess) {
  73     return;
  74   }
  75
  76   if (IsValid()) {
  77 #ifdef XP_WIN
  78     if (!CloseHandle(mHandle)) {
  79       NS_WARNING("Failed to close file handle for current process!");
  80     }
  81 #else // XP_WIN
  82     HANDLE_EINTR(close(mHandle));
  83 #endif
  84     mHandle = INVALID_HANDLE;
  85   }
  86 }
  87
  88 FileDescriptor::PickleType
  89 FileDescriptor::ShareTo(const FileDescriptor::IPDLPrivate&,
  90                         FileDescriptor::ProcessHandle aOtherProcess) const
  91 {
  92   PlatformHandleType newHandle;
  93 #ifdef XP_WIN
  94   if (IsValid()) {
  95     if (DuplicateHandle(GetCurrentProcess(), mHandle, aOtherProcess,
  96                         &newHandle, 0, FALSE, DUPLICATE_SAME_ACCESS)) {
  97       return newHandle;
  98     }
  99     NS_WARNING("Failed to duplicate file handle for other process!");
 100   }
 101   return INVALID_HANDLE;
 102 #else // XP_WIN
 103   if (IsValid()) {
 104     newHandle = dup(mHandle);
 105     if (IsValid(newHandle)) {
 106       return base::FileDescriptor(newHandle, /* auto_close */ true);
 107     }
 108     NS_WARNING("Failed to duplicate file handle for other process!");
 109   }
 110   return base::FileDescriptor();
 111 #endif
 112
 113   MOZ_CRASH("Must not get here!");
 114 }
 115
 116 // static
 117 bool
 118 FileDescriptor::IsValid(PlatformHandleType aHandle)
 119 {
 120   return aHandle != INVALID_HANDLE;
 121 }