Support creating mojo peer connections from named pipes.

mojo/edk/embedder/named_platform_handle_utils_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_handle_utils.h"
+
+#include <sddl.h>
+#include <windows.h>
+
+#include <memory>
+
+#include "base/logging.h"
+#include "base/win/windows_version.h"
+#include "mojo/edk/embedder/named_platform_handle.h"
+
+namespace mojo {
+namespace edk {
+
+ScopedPlatformHandle CreateClientHandle(
+    const NamedPlatformHandle& named_handle) {
+  if (!named_handle.is_valid())
+    return ScopedPlatformHandle();
+
+  base::string16 pipe_name = named_handle.pipe_name();
+
+  // Note: This may block.
+  if (!WaitNamedPipeW(pipe_name.c_str(), NMPWAIT_USE_DEFAULT_WAIT))
+    return ScopedPlatformHandle();
+
+  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(pipe_name.c_str(), kDesiredAccess,
+                                 0,  // No sharing.
+                                 nullptr, OPEN_EXISTING, kFlags,
+                                 nullptr)));  // No template file.
+  PCHECK(handle.is_valid());
+  return handle;
+}
+
+ScopedPlatformHandle CreateServerHandle(const NamedPlatformHandle& named_handle,
+                                        bool enforce_uniqueness) {
+  if (!named_handle.is_valid())
+    return ScopedPlatformHandle();
+
+  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 = enforce_uniqueness
+                              ? PIPE_ACCESS_DUPLEX | FILE_FLAG_OVERLAPPED |
+                                    FILE_FLAG_FIRST_PIPE_INSTANCE
+                              : PIPE_ACCESS_DUPLEX | FILE_FLAG_OVERLAPPED;
+  const DWORD kPipeMode =
+      PIPE_TYPE_BYTE | PIPE_READMODE_BYTE | PIPE_REJECT_REMOTE_CLIENTS;
+  PlatformHandle handle(
+      CreateNamedPipeW(named_handle.pipe_name().c_str(), kOpenMode, kPipeMode,
+                       enforce_uniqueness ? 1 : 255,  // Max instances.
+                       4096,                          // Out buffer size.
+                       4096,                          // In buffer size.
+                       5000,  // Timeout in milliseconds.
+                       &security_attributes));
+  handle.needs_connection = true;
+  return ScopedPlatformHandle(handle);
+}
+
+}  // namespace edk
+}  // namespace mojo