gecko-dev/ipc/nfc/NfcConnector.cpp

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* vim: set sw=2 ts=8 et ft=cpp: */

/* 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 "NfcConnector.h"
#include <fcntl.h>
#include <sys/un.h>
#include "nsISupportsImpl.h" // for MOZ_COUNT_CTOR, MOZ_COUNT_DTOR
#include "nsThreadUtils.h" // For NS_IsMainThread.

namespace mozilla {
namespace ipc {

NfcConnector::NfcConnector(const nsACString& aAddressString)
  : mAddressString(aAddressString)
{
  MOZ_COUNT_CTOR_INHERITED(NfcConnector, UnixSocketConnector);
}

NfcConnector::~NfcConnector()
{
  MOZ_COUNT_DTOR_INHERITED(NfcConnector, UnixSocketConnector);
}

nsresult
NfcConnector::CreateSocket(int& aFd) const
{
  aFd = socket(AF_LOCAL, SOCK_SEQPACKET, 0);
  if (aFd < 0) {
    NS_WARNING("Could not open NFC socket!");
    return NS_ERROR_FAILURE;
  }

  return NS_OK;
}

nsresult
NfcConnector::SetSocketFlags(int aFd) const
{
  static const int sReuseAddress = 1;

  // Set close-on-exec bit.
  int flags = TEMP_FAILURE_RETRY(fcntl(aFd, F_GETFD));
  if (flags < 0) {
    return NS_ERROR_FAILURE;
  }
  flags |= FD_CLOEXEC;
  int res = TEMP_FAILURE_RETRY(fcntl(aFd, F_SETFD, flags));
  if (res < 0) {
    return NS_ERROR_FAILURE;
  }

  // Set non-blocking status flag.
  flags = TEMP_FAILURE_RETRY(fcntl(aFd, F_GETFL));
  if (flags < 0) {
    return NS_ERROR_FAILURE;
  }
  flags |= O_NONBLOCK;
  res = TEMP_FAILURE_RETRY(fcntl(aFd, F_SETFL, flags));
  if (res < 0) {
    return NS_ERROR_FAILURE;
  }

  // Set socket addr to be reused even if kernel is still waiting to close.
  res = setsockopt(aFd, SOL_SOCKET, SO_REUSEADDR, &sReuseAddress,
                   sizeof(sReuseAddress));
  if (res < 0) {
    return NS_ERROR_FAILURE;
  }

  return NS_OK;
}

nsresult
NfcConnector::CreateAddress(struct sockaddr& aAddress,
                            socklen_t& aAddressLength) const
{
  static const size_t sNameOffset = 1;

  struct sockaddr_un* address =
    reinterpret_cast<struct sockaddr_un*>(&aAddress);

  size_t namesiz = mAddressString.Length() + 1; // include trailing '\0'

  if (NS_WARN_IF((sNameOffset + namesiz) > sizeof(address->sun_path))) {
    return NS_ERROR_FAILURE;
  }

  address->sun_family = AF_UNIX;
  memset(address->sun_path, '\0', sNameOffset); // abstract socket
  memcpy(address->sun_path + sNameOffset, mAddressString.get(), namesiz);

  aAddressLength =
    offsetof(struct sockaddr_un, sun_path) + sNameOffset + namesiz;

  return NS_OK;
}

// |UnixSocketConnector|
//

nsresult
NfcConnector::ConvertAddressToString(const struct sockaddr& aAddress,
                                     socklen_t aAddressLength,
                                     nsACString& aAddressString)
{
  MOZ_ASSERT(aAddress.sa_family == AF_UNIX);

  const struct sockaddr_un* un =
    reinterpret_cast<const struct sockaddr_un*>(&aAddress);

  size_t len = aAddressLength - offsetof(struct sockaddr_un, sun_path);

  aAddressString.Assign(un->sun_path, len);

  return NS_OK;
}

nsresult
NfcConnector::CreateListenSocket(struct sockaddr* aAddress,
                                 socklen_t* aAddressLength,
                                 int& aListenFd)
{
  ScopedClose fd;

  nsresult rv = CreateSocket(fd.rwget());
  if (NS_FAILED(rv)) {
    return rv;
  }
  rv = SetSocketFlags(fd);
  if (NS_FAILED(rv)) {
    return rv;
  }
  if (aAddress && aAddressLength) {
    rv = CreateAddress(*aAddress, *aAddressLength);
    if (NS_FAILED(rv)) {
      return rv;
    }
  }

  aListenFd = fd.forget();

  return NS_OK;
}

nsresult
NfcConnector::AcceptStreamSocket(int aListenFd,
                                 struct sockaddr* aAddress,
                                 socklen_t* aAddressLength,
                                 int& aStreamFd)
{
  ScopedClose fd(
    TEMP_FAILURE_RETRY(accept(aListenFd, aAddress, aAddressLength)));
  if (fd < 0) {
    NS_WARNING("Cannot accept file descriptor!");
    return NS_ERROR_FAILURE;
  }
  nsresult rv = SetSocketFlags(fd);
  if (NS_FAILED(rv)) {
    return rv;
  }

  aStreamFd = fd.forget();

  return NS_OK;
}

nsresult
NfcConnector::CreateStreamSocket(struct sockaddr* aAddress,
                                 socklen_t* aAddressLength,
                                 int& aStreamFd)
{
  ScopedClose fd;

  nsresult rv = CreateSocket(fd.rwget());
  if (NS_FAILED(rv)) {
    return rv;
  }
  rv = SetSocketFlags(fd);
  if (NS_FAILED(rv)) {
    return rv;
  }
  if (aAddress && aAddressLength) {
    rv = CreateAddress(*aAddress, *aAddressLength);
    if (NS_FAILED(rv)) {
      return rv;
    }
  }

  aStreamFd = fd.forget();

  return NS_OK;
}

nsresult
NfcConnector::Duplicate(UnixSocketConnector*& aConnector)
{
  aConnector = new NfcConnector(*this);

  return NS_OK;
}

}
}