gecko-dev/ipc/glue/InputStreamUtils.cpp

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "InputStreamUtils.h"

#include "nsIIPCSerializableInputStream.h"

#include "mozilla/Assertions.h"
#include "mozilla/dom/File.h"
#include "mozilla/dom/ipc/BlobChild.h"
#include "mozilla/dom/ipc/BlobParent.h"
#include "nsComponentManagerUtils.h"
#include "nsDebug.h"
#include "nsID.h"
#include "nsIXULRuntime.h"
#include "nsMIMEInputStream.h"
#include "nsMultiplexInputStream.h"
#include "nsNetCID.h"
#include "nsStringStream.h"
#include "nsXULAppAPI.h"

using namespace mozilla::dom;

namespace {

NS_DEFINE_CID(kStringInputStreamCID, NS_STRINGINPUTSTREAM_CID);
NS_DEFINE_CID(kFileInputStreamCID, NS_LOCALFILEINPUTSTREAM_CID);
NS_DEFINE_CID(kPartialFileInputStreamCID, NS_PARTIALLOCALFILEINPUTSTREAM_CID);
NS_DEFINE_CID(kBufferedInputStreamCID, NS_BUFFEREDINPUTSTREAM_CID);
NS_DEFINE_CID(kMIMEInputStreamCID, NS_MIMEINPUTSTREAM_CID);
NS_DEFINE_CID(kMultiplexInputStreamCID, NS_MULTIPLEXINPUTSTREAM_CID);

} // namespace

namespace mozilla {
namespace ipc {

void
SerializeInputStream(nsIInputStream* aInputStream,
                     InputStreamParams& aParams,
                     nsTArray<FileDescriptor>& aFileDescriptors)
{
  MOZ_ASSERT(aInputStream);

  nsCOMPtr<nsIIPCSerializableInputStream> serializable =
    do_QueryInterface(aInputStream);
  if (!serializable) {
    MOZ_CRASH("Input stream is not serializable!");
  }

  serializable->Serialize(aParams, aFileDescriptors);

  if (aParams.type() == InputStreamParams::T__None) {
    MOZ_CRASH("Serialize failed!");
  }
}

void
SerializeInputStream(nsIInputStream* aInputStream,
                     OptionalInputStreamParams& aParams,
                     nsTArray<FileDescriptor>& aFileDescriptors)
{
  if (aInputStream) {
    InputStreamParams params;
    SerializeInputStream(aInputStream, params, aFileDescriptors);
    aParams = params;
  }
  else {
    aParams = mozilla::void_t();
  }
}

already_AddRefed<nsIInputStream>
DeserializeInputStream(const InputStreamParams& aParams,
                       const nsTArray<FileDescriptor>& aFileDescriptors)
{
  nsCOMPtr<nsIInputStream> stream;
  nsCOMPtr<nsIIPCSerializableInputStream> serializable;

  switch (aParams.type()) {
    case InputStreamParams::TStringInputStreamParams:
      serializable = do_CreateInstance(kStringInputStreamCID);
      break;

    case InputStreamParams::TFileInputStreamParams:
      serializable = do_CreateInstance(kFileInputStreamCID);
      break;

    case InputStreamParams::TPartialFileInputStreamParams:
      serializable = do_CreateInstance(kPartialFileInputStreamCID);
      break;

    case InputStreamParams::TBufferedInputStreamParams:
      serializable = do_CreateInstance(kBufferedInputStreamCID);
      break;

    case InputStreamParams::TMIMEInputStreamParams:
      serializable = do_CreateInstance(kMIMEInputStreamCID);
      break;

    case InputStreamParams::TMultiplexInputStreamParams:
      serializable = do_CreateInstance(kMultiplexInputStreamCID);
      break;

    // When the input stream already exists in this process, all we need to do
    // is retrieve the original instead of sending any data over the wire.
    case InputStreamParams::TRemoteInputStreamParams: {
      if (NS_WARN_IF(!XRE_IsParentProcess())) {
        return nullptr;
      }

      const nsID& id = aParams.get_RemoteInputStreamParams().id();

      RefPtr<BlobImpl> blobImpl = BlobParent::GetBlobImplForID(id);

      MOZ_ASSERT(blobImpl, "Invalid blob contents");

      // If fetching the internal stream fails, we ignore it and return a
      // null stream.
      ErrorResult rv;
      nsCOMPtr<nsIInputStream> stream;
      blobImpl->GetInternalStream(getter_AddRefs(stream), rv);
      if (NS_WARN_IF(rv.Failed()) || !stream) {
        NS_WARNING("Couldn't obtain a valid stream from the blob");
        rv.SuppressException();
      }
      return stream.forget();
    }

    case InputStreamParams::TSameProcessInputStreamParams: {
      MOZ_ASSERT(aFileDescriptors.IsEmpty());

      const SameProcessInputStreamParams& params =
        aParams.get_SameProcessInputStreamParams();

      stream = dont_AddRef(
        reinterpret_cast<nsIInputStream*>(params.addRefedInputStream()));
      MOZ_ASSERT(stream);

      return stream.forget();
    }

    default:
      MOZ_ASSERT(false, "Unknown params!");
      return nullptr;
  }

  MOZ_ASSERT(serializable);

  if (!serializable->Deserialize(aParams, aFileDescriptors)) {
    MOZ_ASSERT(false, "Deserialize failed!");
    return nullptr;
  }

  stream = do_QueryInterface(serializable);
  MOZ_ASSERT(stream);

  return stream.forget();
}

already_AddRefed<nsIInputStream>
DeserializeInputStream(const OptionalInputStreamParams& aParams,
                       const nsTArray<FileDescriptor>& aFileDescriptors)
{
  nsCOMPtr<nsIInputStream> stream;

  switch (aParams.type()) {
    case OptionalInputStreamParams::Tvoid_t:
      // Leave stream null.
      break;

    case OptionalInputStreamParams::TInputStreamParams:
      stream = DeserializeInputStream(aParams.get_InputStreamParams(),
                                      aFileDescriptors);
      break;

    default:
      MOZ_ASSERT(false, "Unknown params!");
  }

  return stream.forget();
}

} // namespace ipc
} // namespace mozilla