Support creating mojo peer connections from named pipes.

mojo/edk/embedder/named_platform_channel_pair_win.cc

 // Copyright 2016 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 "mojo/edk/embedder/named_platform_channel_pair.h"
 
-#include <sddl.h>
 #include <windows.h>
 
 #include <memory>
 #include <string>
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/rand_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/stringprintf.h"
+#include "base/strings/utf_string_conversions.h"
 #include "base/win/windows_version.h"
+#include "mojo/edk/embedder/named_platform_handle_utils.h"
 #include "mojo/edk/embedder/platform_handle.h"
 
 namespace mojo {
 namespace edk {
 
 namespace {
 
 const char kMojoNamedPlatformChannelPipeSwitch[] =
     "mojo-named-platform-channel-pipe";
 
 std::wstring GeneratePipeName() {
-  return base::StringPrintf(L"\\\\.\\pipe\\mojo.%u.%u.%I64u",
-                            GetCurrentProcessId(), GetCurrentThreadId(),
-                            base::RandUint64());
-
+  return base::StringPrintf(L"%u.%u.%I64u", GetCurrentProcessId(),
+                            GetCurrentThreadId(), base::RandUint64());
 }
 
 }  // namespace
 
-NamedPlatformChannelPair::NamedPlatformChannelPair() {
-  pipe_name_ = GeneratePipeName();
-
-  PSECURITY_DESCRIPTOR security_desc = nullptr;
-  ULONG security_desc_len = 0;
-  // Create a DACL to grant:
-  // GA = Generic All
-  // access to:
-  // SY = LOCAL_SYSTEM
-  // BA = BUILTIN_ADMINISTRATORS
-  // OW = OWNER_RIGHTS
-  PCHECK(ConvertStringSecurityDescriptorToSecurityDescriptor(
-      L"D:(A;;GA;;;SY)(A;;GA;;;BA)(A;;GA;;;OW)",
-      SDDL_REVISION_1, &security_desc, &security_desc_len));
-  std::unique_ptr<void, decltype(::LocalFree)*> p(security_desc, ::LocalFree);
-  SECURITY_ATTRIBUTES security_attributes = {
-      sizeof(SECURITY_ATTRIBUTES), security_desc, FALSE };
-
-  const DWORD kOpenMode =
-      PIPE_ACCESS_DUPLEX | FILE_FLAG_OVERLAPPED | FILE_FLAG_FIRST_PIPE_INSTANCE;
-  const DWORD kPipeMode =
-      PIPE_TYPE_BYTE | PIPE_READMODE_BYTE | PIPE_REJECT_REMOTE_CLIENTS;
-  PlatformHandle handle(
-      CreateNamedPipeW(pipe_name_.c_str(), kOpenMode, kPipeMode,
-                       1,           // Max instances.
-                       4096,        // Out buffer size.
-                       4096,        // In buffer size.
-                       5000,        // Timeout in milliseconds.
-                       &security_attributes));
-  handle.needs_connection = true;
-  server_handle_.reset(handle);
+NamedPlatformChannelPair::NamedPlatformChannelPair()
+    : pipe_handle_(GeneratePipeName()) {
+  server_handle_ = CreateServerHandle(pipe_handle_, true);
   PCHECK(server_handle_.is_valid());
 }
 
 NamedPlatformChannelPair::~NamedPlatformChannelPair() {}
 
 ScopedPlatformHandle NamedPlatformChannelPair::PassServerHandle() {
   return std::move(server_handle_);
 }
 
 // static
 ScopedPlatformHandle
 NamedPlatformChannelPair::PassClientHandleFromParentProcess(
     const base::CommandLine& command_line) {
-  std::wstring client_handle_string =
-      command_line.GetSwitchValueNative(kMojoNamedPlatformChannelPipeSwitch);
+  // In order to support passing the pipe name on the command line, the pipe
+  // handle is lazily created from the pipe name when requested.
+  NamedPlatformHandle handle(
+      command_line.GetSwitchValueNative(kMojoNamedPlatformChannelPipeSwitch));
 
-  if (client_handle_string.empty())
+  if (!handle.is_valid())
     return ScopedPlatformHandle();
 
-  // Note: This may block.
-  BOOL ok = WaitNamedPipeW(client_handle_string.c_str(),
-                           NMPWAIT_USE_DEFAULT_WAIT);
-  if (!ok)
-    return ScopedPlatformHandle();
-
-  // In order to support passing the pipe name on the command line, the pipe
-  // handle is lazily created from the pipe name when requested.
-  const DWORD kDesiredAccess = GENERIC_READ | GENERIC_WRITE;
-  // The SECURITY_ANONYMOUS flag means that the server side cannot impersonate
-  // the client.
-  const DWORD kFlags =
-      SECURITY_SQOS_PRESENT | SECURITY_ANONYMOUS | FILE_FLAG_OVERLAPPED;
-  ScopedPlatformHandle handle(
-      PlatformHandle(CreateFileW(client_handle_string.c_str(), kDesiredAccess,
-                                 0,  // No sharing.
-                                 nullptr, OPEN_EXISTING, kFlags,
-                                 nullptr)));  // No template file.
-  PCHECK(handle.is_valid());
-  return handle;
+  return CreateClientHandle(handle);
 }
 
 void NamedPlatformChannelPair::PrepareToPassClientHandleToChildProcess(
     base::CommandLine* command_line) const {
   DCHECK(command_line);
 
   // Log a warning if the command line already has the switch, but "clobber" it
   // anyway, since it's reasonably likely that all the switches were just copied
   // from the parent.
   LOG_IF(WARNING,
          command_line->HasSwitch(kMojoNamedPlatformChannelPipeSwitch))
       << "Child command line already has switch --"
       << kMojoNamedPlatformChannelPipeSwitch << "="
       << command_line->GetSwitchValueNative(
           kMojoNamedPlatformChannelPipeSwitch);
   // (Any existing switch won't actually be removed from the command line, but
   // the last one appended takes precedence.)
-  command_line->AppendSwitchNative(
-      kMojoNamedPlatformChannelPipeSwitch, pipe_name_);
+  command_line->AppendSwitchNative(kMojoNamedPlatformChannelPipeSwitch,
+                                   pipe_handle_.name);
 }
 
 }  // namespace edk
 }  // namespace mojo