// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

#include "bin/io_buffer.h"
#include "bin/isolate_data.h"
#include "bin/dartutils.h"
#include "bin/socket.h"
#include "bin/thread.h"
#include "bin/lockers.h"
#include "bin/utils.h"

#include "platform/globals.h"
#include "platform/utils.h"

#include "include/dart_api.h"

namespace dart {
namespace bin {

static const int kSocketIdNativeField = 0;


ListeningSocketRegistry *globalTcpListeningSocketRegistry = NULL;


void ListeningSocketRegistry::Initialize() {
  ASSERT(globalTcpListeningSocketRegistry == NULL);
  globalTcpListeningSocketRegistry = new ListeningSocketRegistry();
}


ListeningSocketRegistry *ListeningSocketRegistry::Instance() {
  return globalTcpListeningSocketRegistry;
}


void ListeningSocketRegistry::Cleanup() {
  delete globalTcpListeningSocketRegistry;
  globalTcpListeningSocketRegistry = NULL;
}


Dart_Handle ListeningSocketRegistry::CreateBindListen(Dart_Handle socket_object,
                                                      RawAddr addr,
                                                      intptr_t backlog,
                                                      bool v6_only,
                                                      bool shared) {
  MutexLocker ml(ListeningSocketRegistry::mutex_);

  intptr_t port = SocketAddress::GetAddrPort(addr);

  SocketsIterator it = sockets_by_port_.find(port);
  OSSocket *first_os_socket = NULL;
  if (it != sockets_by_port_.end()) {
    first_os_socket = it->second;
  }

  if (first_os_socket != NULL) {
    // There is already a socket listening on this port. We need to ensure
    // that if there is one also listening on the same address, it was created
    // with `shared = true`, ...

    OSSocket *os_socket = it->second;
    OSSocket *os_socket_same_addr = findOSSocketWithAddress(os_socket, addr);

    if (os_socket_same_addr != NULL) {
      if (!os_socket_same_addr->shared || !shared) {
        OSError os_error(-1,
                         "The shared flag to bind() needs to be `true` if "
                         "binding multiple times on the same (address, port) "
                         "combination.",
                        OSError::kUnknown);
        return DartUtils::NewDartOSError(&os_error);
      }
      if (os_socket_same_addr->v6_only != v6_only) {
        OSError os_error(-1,
                         "The v6Only flag to bind() needs to be the same if "
                         "binding multiple times on the same (address, port) "
                         "combination.",
                        OSError::kUnknown);
        return DartUtils::NewDartOSError(&os_error);
      }

      // This socket creation is the exact same as the one which originally
      // created the socket. We therefore increment the refcount and reuse
      // the file descriptor.
      os_socket->ref_count++;

      // We set as a side-effect the file descriptor on the dart socket_object.
      Socket::SetSocketIdNativeField(socket_object, os_socket->socketfd);

      return Dart_True();
    }
  }

  // There is no socket listening on that (address, port), so we create new one.
  intptr_t socketfd = ServerSocket::CreateBindListen(addr, backlog, v6_only);
  if (socketfd == -5) {
    OSError os_error(-1, "Invalid host", OSError::kUnknown);
    return DartUtils::NewDartOSError(&os_error);
  }
  if (socketfd < 0) {
    OSError error;
    return DartUtils::NewDartOSError(&error);
  }
  if (!ServerSocket::StartAccept(socketfd)) {
    OSError os_error(-1, "Failed to start accept", OSError::kUnknown);
    return DartUtils::NewDartOSError(&os_error);
  }
  intptr_t allocated_port = Socket::GetPort(socketfd);
  ASSERT(allocated_port > 0);

  OSSocket *os_socket =
      new OSSocket(addr, allocated_port, v6_only, shared, socketfd);
  os_socket->ref_count = 1;
  os_socket->next = first_os_socket;
  sockets_by_port_[allocated_port] = os_socket;
  sockets_by_fd_[socketfd] = os_socket;

  // We set as a side-effect the port on the dart socket_object.
  Socket::SetSocketIdNativeField(socket_object, socketfd);

  return Dart_True();
}


bool ListeningSocketRegistry::CloseSafe(intptr_t socketfd) {
  ASSERT(!mutex_->TryLock());

  SocketsIterator it = sockets_by_fd_.find(socketfd);
  if (it != sockets_by_fd_.end()) {
    OSSocket *os_socket = it->second;

    ASSERT(os_socket->ref_count > 0);
    os_socket->ref_count--;
    if (os_socket->ref_count == 0) {
      // We free the OS socket by removing it from two datastructures.
      sockets_by_fd_.erase(socketfd);

      OSSocket *prev = NULL;
      OSSocket *current = sockets_by_port_[os_socket->port];
      while (current != os_socket) {
        ASSERT(current != NULL);
        prev = current;
        current = current->next;
      }

      if (prev == NULL && current->next == NULL) {
        // Remove last element from the list.
        sockets_by_port_.erase(os_socket->port);
      } else if (prev == NULL) {
        // Remove first element of the list.
        sockets_by_port_[os_socket->port] = current->next;
      } else {
        // Remove element from the list which is not the first one.
        prev->next = os_socket->next;
      }

      delete os_socket;
      return true;
    }
    return false;
  } else {
    // It should be impossible for the event handler to close something that
    // hasn't been created before.
    UNREACHABLE();
    return false;
  }
}


void FUNCTION_NAME(InternetAddress_Parse)(Dart_NativeArguments args) {
  const char* address =
      DartUtils::GetStringValue(Dart_GetNativeArgument(args, 0));
  ASSERT(address != NULL);
  RawAddr raw;
  memset(&raw, 0, sizeof(raw));
  int type = strchr(address, ':') == NULL ? SocketAddress::TYPE_IPV4
                                          : SocketAddress::TYPE_IPV6;
  if (type == SocketAddress::TYPE_IPV4) {
    raw.addr.sa_family = AF_INET;
  } else {
    raw.addr.sa_family = AF_INET6;
  }
  bool ok = Socket::ParseAddress(type, address, &raw);
  if (!ok) {
    Dart_SetReturnValue(args, Dart_Null());
  } else {
    Dart_SetReturnValue(args, SocketAddress::ToTypedData(raw));
  }
}


void FUNCTION_NAME(Socket_CreateConnect)(Dart_NativeArguments args) {
  RawAddr addr;
  SocketAddress::GetSockAddr(Dart_GetNativeArgument(args, 1), &addr);
  Dart_Handle port_arg = Dart_GetNativeArgument(args, 2);
  int64_t port = DartUtils::GetInt64ValueCheckRange(port_arg, 0, 65535);
  SocketAddress::SetAddrPort(&addr, static_cast<intptr_t>(port));
  intptr_t socket = Socket::CreateConnect(addr);
  OSError error;
  if (socket >= 0) {
    Socket::SetSocketIdNativeField(Dart_GetNativeArgument(args, 0), socket);
    Dart_SetReturnValue(args, Dart_True());
  } else {
    Dart_SetReturnValue(args, DartUtils::NewDartOSError(&error));
  }
}


void FUNCTION_NAME(Socket_CreateBindConnect)(Dart_NativeArguments args) {
  RawAddr addr;
  SocketAddress::GetSockAddr(Dart_GetNativeArgument(args, 1), &addr);
  Dart_Handle port_arg = Dart_GetNativeArgument(args, 2);
  int64_t port = DartUtils::GetInt64ValueCheckRange(port_arg, 0, 65535);
  SocketAddress::SetAddrPort(&addr, static_cast<intptr_t>(port));
  RawAddr sourceAddr;
  SocketAddress::GetSockAddr(Dart_GetNativeArgument(args, 3), &sourceAddr);
  intptr_t socket = Socket::CreateBindConnect(addr, sourceAddr);
  OSError error;
  if (socket >= 0) {
    Socket::SetSocketIdNativeField(Dart_GetNativeArgument(args, 0), socket);
    Dart_SetReturnValue(args, Dart_True());
  } else {
    Dart_SetReturnValue(args, DartUtils::NewDartOSError(&error));
  }
}


void FUNCTION_NAME(Socket_CreateBindDatagram)(Dart_NativeArguments args) {
  RawAddr addr;
  SocketAddress::GetSockAddr(Dart_GetNativeArgument(args, 1), &addr);
  Dart_Handle port_arg = Dart_GetNativeArgument(args, 2);
  int64_t port = DartUtils::GetInt64ValueCheckRange(port_arg, 0, 65535);
  SocketAddress::SetAddrPort(&addr, port);
  bool reuse_addr = DartUtils::GetBooleanValue(Dart_GetNativeArgument(args, 3));
  intptr_t socket = Socket::CreateBindDatagram(addr, reuse_addr);
  if (socket >= 0) {
    Socket::SetSocketIdNativeField(Dart_GetNativeArgument(args, 0), socket);
    Dart_SetReturnValue(args, Dart_True());
  } else {
    OSError error;
    Dart_SetReturnValue(args, DartUtils::NewDartOSError(&error));
  }
}


void FUNCTION_NAME(Socket_Available)(Dart_NativeArguments args) {
  intptr_t socket =
      Socket::GetSocketIdNativeField(Dart_GetNativeArgument(args, 0));
  intptr_t available = Socket::Available(socket);
  if (available >= 0) {
    Dart_SetReturnValue(args, Dart_NewInteger(available));
  } else {
    // Available failed. Mark socket as having data, to trigger a future read
    // event where the actual error can be reported.
    Dart_SetReturnValue(args, Dart_NewInteger(1));
  }
}


void FUNCTION_NAME(Socket_Read)(Dart_NativeArguments args) {
  static bool short_socket_reads = Dart_IsVMFlagSet("short_socket_read");
  intptr_t socket =
      Socket::GetSocketIdNativeField(Dart_GetNativeArgument(args, 0));
  int64_t length = 0;
  if (DartUtils::GetInt64Value(Dart_GetNativeArgument(args, 1), &length)) {
    if (short_socket_reads) {
      length = (length + 1) / 2;
    }
    uint8_t* buffer = NULL;
    Dart_Handle result = IOBuffer::Allocate(length, &buffer);
    if (Dart_IsError(result)) Dart_PropagateError(result);
    ASSERT(buffer != NULL);
    intptr_t bytes_read = Socket::Read(socket, buffer, length);
    if (bytes_read == length) {
      Dart_SetReturnValue(args, result);
    } else if (bytes_read > 0) {
      uint8_t* new_buffer = NULL;
      Dart_Handle new_result = IOBuffer::Allocate(bytes_read, &new_buffer);
      if (Dart_IsError(new_result)) Dart_PropagateError(new_result);
      ASSERT(new_buffer != NULL);
      memmove(new_buffer, buffer, bytes_read);
      Dart_SetReturnValue(args, new_result);
    } else if (bytes_read == 0) {
      // On MacOS when reading from a tty Ctrl-D will result in reading one
      // less byte then reported as available.
      Dart_SetReturnValue(args, Dart_Null());
    } else {
      ASSERT(bytes_read == -1);
      Dart_SetReturnValue(args, DartUtils::NewDartOSError());
    }
  } else {
    OSError os_error(-1, "Invalid argument", OSError::kUnknown);
    Dart_Handle err = DartUtils::NewDartOSError(&os_error);
    if (Dart_IsError(err)) Dart_PropagateError(err);
    Dart_SetReturnValue(args, err);
  }
}


void FUNCTION_NAME(Socket_RecvFrom)(Dart_NativeArguments args) {
  intptr_t socket =
      Socket::GetSocketIdNativeField(Dart_GetNativeArgument(args, 0));

  // TODO(sgjesse): Use a MTU value here. Only the loopback adapter can
  // handle 64k datagrams.
  IsolateData* isolate_data =
      reinterpret_cast<IsolateData*>(Dart_CurrentIsolateData());
  if (isolate_data->udp_receive_buffer == NULL) {
    isolate_data->udp_receive_buffer =
        reinterpret_cast<uint8_t*>(malloc(65536));
  }
  RawAddr addr;
  intptr_t bytes_read =
      Socket::RecvFrom(socket, isolate_data->udp_receive_buffer, 65536, &addr);
  if (bytes_read == 0) {
    Dart_SetReturnValue(args, Dart_Null());
    return;
  }
  if (bytes_read < 0) {
    ASSERT(bytes_read == -1);
    Dart_SetReturnValue(args, DartUtils::NewDartOSError());
    return;
  }
  // Datagram data read. Copy into buffer of the exact size,
  ASSERT(bytes_read > 0);
  uint8_t* data_buffer = NULL;
  Dart_Handle data = IOBuffer::Allocate(bytes_read, &data_buffer);
  if (Dart_IsError(data)) Dart_PropagateError(data);
  ASSERT(data_buffer != NULL);
  memmove(data_buffer, isolate_data->udp_receive_buffer, bytes_read);

  // Get the port and clear it in the sockaddr structure.
  int port = SocketAddress::GetAddrPort(addr);
  if (addr.addr.sa_family == AF_INET) {
    addr.in.sin_port = 0;
  } else {
    ASSERT(addr.addr.sa_family == AF_INET6);
    addr.in6.sin6_port = 0;
  }
  // Format the address to a string using the numeric format.
  char numeric_address[INET6_ADDRSTRLEN];
  Socket::FormatNumericAddress(addr, numeric_address, INET6_ADDRSTRLEN);

  // Create a Datagram object with the data and sender address and port.
  const int kNumArgs = 4;
  Dart_Handle dart_args[kNumArgs];
  dart_args[0] = data;
  dart_args[1] = Dart_NewStringFromCString(numeric_address);
  if (Dart_IsError(dart_args[1])) Dart_PropagateError(dart_args[1]);
  dart_args[2] = SocketAddress::ToTypedData(addr);
  dart_args[3] = Dart_NewInteger(port);
  if (Dart_IsError(dart_args[3])) Dart_PropagateError(dart_args[3]);
  // TODO(sgjesse): Cache the _makeDatagram function somewhere.
  Dart_Handle io_lib =
      Dart_LookupLibrary(DartUtils::NewString("dart:io"));
  if (Dart_IsError(io_lib)) Dart_PropagateError(io_lib);
  Dart_Handle result =
      Dart_Invoke(io_lib,
                  DartUtils::NewString("_makeDatagram"),
                  kNumArgs,
                  dart_args);
  if (Dart_IsError(result)) Dart_PropagateError(result);
  Dart_SetReturnValue(args, result);
}


void FUNCTION_NAME(Socket_WriteList)(Dart_NativeArguments args) {
  static bool short_socket_writes = Dart_IsVMFlagSet("short_socket_write");
  intptr_t socket =
      Socket::GetSocketIdNativeField(Dart_GetNativeArgument(args, 0));
  Dart_Handle buffer_obj = Dart_GetNativeArgument(args, 1);
  ASSERT(Dart_IsList(buffer_obj));
  intptr_t offset =
      DartUtils::GetIntptrValue(Dart_GetNativeArgument(args, 2));
  intptr_t length =
      DartUtils::GetIntptrValue(Dart_GetNativeArgument(args, 3));
  bool short_write = false;
  if (short_socket_writes) {
    if (length > 1) short_write = true;
    length = (length + 1) / 2;
  }
  Dart_TypedData_Type type;
  uint8_t* buffer = NULL;
  intptr_t len;
  Dart_Handle result = Dart_TypedDataAcquireData(
      buffer_obj, &type, reinterpret_cast<void**>(&buffer), &len);
  if (Dart_IsError(result)) Dart_PropagateError(result);
  ASSERT((offset + length) <= len);
  buffer += offset;
  intptr_t bytes_written = Socket::Write(socket, buffer, length);
  if (bytes_written >= 0) {
    Dart_TypedDataReleaseData(buffer_obj);
    if (short_write) {
      // If the write was forced 'short', indicate by returning the negative
      // number of bytes. A forced short write may not trigger a write event.
      Dart_SetReturnValue(args, Dart_NewInteger(-bytes_written));
    } else {
      Dart_SetReturnValue(args, Dart_NewInteger(bytes_written));
    }
  } else {
    // Extract OSError before we release data, as it may override the error.
    OSError os_error;
    Dart_TypedDataReleaseData(buffer_obj);
    Dart_SetReturnValue(args, DartUtils::NewDartOSError(&os_error));
  }
}


void FUNCTION_NAME(Socket_SendTo)(Dart_NativeArguments args) {
  intptr_t socket =
      Socket::GetSocketIdNativeField(Dart_GetNativeArgument(args, 0));
  Dart_Handle buffer_obj = Dart_GetNativeArgument(args, 1);
  intptr_t offset =
      DartUtils::GetIntptrValue(Dart_GetNativeArgument(args, 2));
  intptr_t length =
      DartUtils::GetIntptrValue(Dart_GetNativeArgument(args, 3));
  Dart_Handle address_obj = Dart_GetNativeArgument(args, 4);
  ASSERT(Dart_IsList(address_obj));
  RawAddr addr;
  SocketAddress::GetSockAddr(address_obj, &addr);
  int64_t port = DartUtils::GetInt64ValueCheckRange(
      Dart_GetNativeArgument(args, 5),
      0,
      65535);
  SocketAddress::SetAddrPort(&addr, port);
  Dart_TypedData_Type type;
  uint8_t* buffer = NULL;
  intptr_t len;
  Dart_Handle result = Dart_TypedDataAcquireData(
      buffer_obj, &type, reinterpret_cast<void**>(&buffer), &len);
  if (Dart_IsError(result)) Dart_PropagateError(result);
  ASSERT((offset + length) <= len);
  buffer += offset;
  intptr_t bytes_written = Socket::SendTo(socket, buffer, length, addr);
  if (bytes_written >= 0) {
    Dart_TypedDataReleaseData(buffer_obj);
    Dart_SetReturnValue(args, Dart_NewInteger(bytes_written));
  } else {
    // Extract OSError before we release data, as it may override the error.
    OSError os_error;
    Dart_TypedDataReleaseData(buffer_obj);
    Dart_SetReturnValue(args, DartUtils::NewDartOSError(&os_error));
  }
}


void FUNCTION_NAME(Socket_GetPort)(Dart_NativeArguments args) {
  intptr_t socket =
      Socket::GetSocketIdNativeField(Dart_GetNativeArgument(args, 0));
  OSError os_error;
  intptr_t port = Socket::GetPort(socket);
  if (port > 0) {
    Dart_SetReturnValue(args, Dart_NewInteger(port));
  } else {
    Dart_SetReturnValue(args, DartUtils::NewDartOSError());
  }
}


void FUNCTION_NAME(Socket_GetRemotePeer)(Dart_NativeArguments args) {
  intptr_t socket =
      Socket::GetSocketIdNativeField(Dart_GetNativeArgument(args, 0));
  OSError os_error;
  intptr_t port = 0;
  SocketAddress* addr = Socket::GetRemotePeer(socket, &port);
  if (addr != NULL) {
    Dart_Handle list = Dart_NewList(2);

    Dart_Handle entry = Dart_NewList(3);
    Dart_ListSetAt(entry, 0, Dart_NewInteger(addr->GetType()));
    Dart_ListSetAt(entry, 1, Dart_NewStringFromCString(addr->as_string()));

    RawAddr raw = addr->addr();
    intptr_t data_length = SocketAddress::GetAddrLength(raw);
    Dart_Handle data = Dart_NewTypedData(Dart_TypedData_kUint8, data_length);
    Dart_ListSetAsBytes(data, 0, reinterpret_cast<uint8_t*>(&raw), data_length);
    Dart_ListSetAt(entry, 2, data);

    Dart_ListSetAt(list, 0, entry);
    Dart_ListSetAt(list, 1, Dart_NewInteger(port));
    Dart_SetReturnValue(args, list);
    delete addr;
  } else {
    Dart_SetReturnValue(args, DartUtils::NewDartOSError());
  }
}


void FUNCTION_NAME(Socket_GetError)(Dart_NativeArguments args) {
  intptr_t socket =
      Socket::GetSocketIdNativeField(Dart_GetNativeArgument(args, 0));
  OSError os_error;
  Socket::GetError(socket, &os_error);
  Dart_SetReturnValue(args, DartUtils::NewDartOSError(&os_error));
}


void FUNCTION_NAME(Socket_GetType)(Dart_NativeArguments args) {
  intptr_t socket =
      Socket::GetSocketIdNativeField(Dart_GetNativeArgument(args, 0));
  OSError os_error;
  intptr_t type = Socket::GetType(socket);
  if (type >= 0) {
    Dart_SetReturnValue(args, Dart_NewInteger(type));
  } else {
    Dart_SetReturnValue(args, DartUtils::NewDartOSError());
  }
}


void FUNCTION_NAME(Socket_GetStdioHandle)(Dart_NativeArguments args) {
  int64_t num = DartUtils::GetInt64ValueCheckRange(
      Dart_GetNativeArgument(args, 1), 0, 2);
  intptr_t socket = Socket::GetStdioHandle(num);
  Socket::SetSocketIdNativeField(Dart_GetNativeArgument(args, 0), socket);
  Dart_SetReturnValue(args, Dart_NewBoolean(socket >= 0));
}


void FUNCTION_NAME(Socket_GetSocketId)(Dart_NativeArguments args) {
  intptr_t id =
      Socket::GetSocketIdNativeField(Dart_GetNativeArgument(args, 0));
  Dart_SetReturnValue(args, Dart_NewInteger(id));
}


void FUNCTION_NAME(Socket_SetSocketId)(Dart_NativeArguments args) {
  intptr_t id =
      DartUtils::GetIntptrValue(Dart_GetNativeArgument(args, 1));
  Socket::SetSocketIdNativeField(Dart_GetNativeArgument(args, 0), id);
}


void FUNCTION_NAME(ServerSocket_CreateBindListen)(Dart_NativeArguments args) {
  RawAddr addr;
  SocketAddress::GetSockAddr(Dart_GetNativeArgument(args, 1), &addr);
  int64_t port = DartUtils::GetInt64ValueCheckRange(
      Dart_GetNativeArgument(args, 2),
      0,
      65535);
  SocketAddress::SetAddrPort(&addr, port);
  int64_t backlog = DartUtils::GetInt64ValueCheckRange(
      Dart_GetNativeArgument(args, 3),
      0,
      65535);
  bool v6_only = DartUtils::GetBooleanValue(Dart_GetNativeArgument(args, 4));
  bool shared = DartUtils::GetBooleanValue(Dart_GetNativeArgument(args, 5));

  Dart_Handle socket_object = Dart_GetNativeArgument(args, 0);
  Dart_Handle result = ListeningSocketRegistry::Instance()->CreateBindListen(
      socket_object, addr, backlog, v6_only, shared);
  Dart_SetReturnValue(args, result);
}


void FUNCTION_NAME(ServerSocket_Accept)(Dart_NativeArguments args) {
  intptr_t socket =
      Socket::GetSocketIdNativeField(Dart_GetNativeArgument(args, 0));
  intptr_t new_socket = ServerSocket::Accept(socket);
  if (new_socket >= 0) {
    Socket::SetSocketIdNativeField(Dart_GetNativeArgument(args, 1), new_socket);
    Dart_SetReturnValue(args, Dart_True());
  } else if (new_socket == ServerSocket::kTemporaryFailure) {
    Dart_SetReturnValue(args, Dart_False());
  } else {
    Dart_SetReturnValue(args, DartUtils::NewDartOSError());
  }
}


CObject* Socket::LookupRequest(const CObjectArray& request) {
  if (request.Length() == 2 &&
      request[0]->IsString() &&
      request[1]->IsInt32()) {
    CObjectString host(request[0]);
    CObjectInt32 type(request[1]);
    CObject* result = NULL;
    OSError* os_error = NULL;
    AddressList<SocketAddress>* addresses =
        Socket::LookupAddress(host.CString(), type.Value(), &os_error);
    if (addresses != NULL) {
      CObjectArray* array = new CObjectArray(
          CObject::NewArray(addresses->count() + 1));
      array->SetAt(0, new CObjectInt32(CObject::NewInt32(0)));
      for (intptr_t i = 0; i < addresses->count(); i++) {
        SocketAddress* addr = addresses->GetAt(i);
        CObjectArray* entry = new CObjectArray(CObject::NewArray(3));

        CObjectInt32* type = new CObjectInt32(
            CObject::NewInt32(addr->GetType()));
        entry->SetAt(0, type);

        CObjectString* as_string = new CObjectString(CObject::NewString(
            addr->as_string()));
        entry->SetAt(1, as_string);

        RawAddr raw = addr->addr();
        CObjectUint8Array* data = SocketAddress::ToCObject(raw);
        entry->SetAt(2, data);

        array->SetAt(i + 1, entry);
      }
      result = array;
      delete addresses;
    } else {
      result = CObject::NewOSError(os_error);
      delete os_error;
    }
    return result;
  }
  return CObject::IllegalArgumentError();
}


CObject* Socket::ReverseLookupRequest(const CObjectArray& request) {
  if (request.Length() == 1 &&
      request[0]->IsTypedData()) {
    CObjectUint8Array addr_object(request[0]);
    RawAddr addr;
    int len = addr_object.Length();
    memset(reinterpret_cast<void*>(&addr), 0, sizeof(RawAddr));
    if (len == sizeof(in_addr)) {
      addr.in.sin_family = AF_INET;
      memmove(reinterpret_cast<void*>(&addr.in.sin_addr),
              addr_object.Buffer(),
              len);
    } else {
      ASSERT(len == sizeof(in6_addr));
      addr.in6.sin6_family = AF_INET6;
      memmove(reinterpret_cast<void*>(&addr.in6.sin6_addr),
              addr_object.Buffer(),
              len);
    }

    OSError* os_error = NULL;
    const intptr_t kMaxHostLength = 1025;
    char host[kMaxHostLength];
    if (Socket::ReverseLookup(addr, host, kMaxHostLength, &os_error)) {
      return new CObjectString(CObject::NewString(host));
    } else {
      CObject* result = CObject::NewOSError(os_error);
      delete os_error;
      return result;
    }
  }
  return CObject::IllegalArgumentError();
}


CObject* Socket::ListInterfacesRequest(const CObjectArray& request) {
  if (request.Length() == 1 &&
      request[0]->IsInt32()) {
    CObjectInt32 type(request[0]);
    CObject* result = NULL;
    OSError* os_error = NULL;
    AddressList<InterfaceSocketAddress>* addresses = Socket::ListInterfaces(
        type.Value(), &os_error);
    if (addresses != NULL) {
      CObjectArray* array = new CObjectArray(
          CObject::NewArray(addresses->count() + 1));
      array->SetAt(0, new CObjectInt32(CObject::NewInt32(0)));
      for (intptr_t i = 0; i < addresses->count(); i++) {
        InterfaceSocketAddress* interface = addresses->GetAt(i);
        SocketAddress* addr = interface->socket_address();
        CObjectArray* entry = new CObjectArray(CObject::NewArray(5));

        CObjectInt32* type = new CObjectInt32(
            CObject::NewInt32(addr->GetType()));
        entry->SetAt(0, type);

        CObjectString* as_string = new CObjectString(CObject::NewString(
            addr->as_string()));
        entry->SetAt(1, as_string);

        RawAddr raw = addr->addr();
        CObjectUint8Array* data = SocketAddress::ToCObject(raw);
        entry->SetAt(2, data);

        CObjectString* interface_name = new CObjectString(CObject::NewString(
            interface->interface_name()));
        entry->SetAt(3, interface_name);

        CObjectInt64* interface_index = new CObjectInt64(CObject::NewInt64(
            interface->interface_index()));
        entry->SetAt(4, interface_index);

        array->SetAt(i + 1, entry);
      }
      result = array;
      delete addresses;
    } else {
      result = CObject::NewOSError(os_error);
      delete os_error;
    }
    return result;
  }
  return CObject::IllegalArgumentError();
}


void FUNCTION_NAME(Socket_GetOption)(Dart_NativeArguments args) {
  intptr_t socket =
      Socket::GetSocketIdNativeField(Dart_GetNativeArgument(args, 0));
  int64_t option = DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 1));
  intptr_t protocol =
      static_cast<intptr_t>(
          DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 2)));
  bool ok = false;
  switch (option) {
    case 0: {  // TCP_NODELAY.
      bool enabled;
      ok = Socket::GetNoDelay(socket, &enabled);
      if (ok) {
        Dart_SetReturnValue(args, enabled ? Dart_True() : Dart_False());
      }
      break;
    }
    case 1: {  // IP_MULTICAST_LOOP.
      bool enabled;
      ok = Socket::GetMulticastLoop(socket, protocol, &enabled);
      if (ok) {
        Dart_SetReturnValue(args, enabled ? Dart_True() : Dart_False());
      }
      break;
    }
    case 2: {  // IP_MULTICAST_TTL.
      int value;
      ok = Socket::GetMulticastHops(socket, protocol, &value);
      if (ok) {
        Dart_SetReturnValue(args, Dart_NewInteger(value));
      }
      break;
    }
    case 3: {  // IP_MULTICAST_IF.
      UNIMPLEMENTED();
      break;
    }
    case 4: {  // IP_BROADCAST.
      bool enabled;
      ok = Socket::GetBroadcast(socket, &enabled);
      if (ok) {
        Dart_SetReturnValue(args, enabled ? Dart_True() : Dart_False());
      }
      break;
    }
    default:
      UNREACHABLE();
      break;
  }
  // In case of failure the return value is not set above.
  if (!ok) {
    Dart_SetReturnValue(args, DartUtils::NewDartOSError());
  }
}


void FUNCTION_NAME(Socket_SetOption)(Dart_NativeArguments args) {
  bool result = false;
  intptr_t socket =
      Socket::GetSocketIdNativeField(Dart_GetNativeArgument(args, 0));
  int64_t option = DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 1));
  int64_t protocol = DartUtils::GetInt64ValueCheckRange(
      Dart_GetNativeArgument(args, 2),
      SocketAddress::TYPE_IPV4,
      SocketAddress::TYPE_IPV6);
  switch (option) {
    case 0:  // TCP_NODELAY.
      result = Socket::SetNoDelay(
          socket, DartUtils::GetBooleanValue(Dart_GetNativeArgument(args, 3)));
      break;
    case 1:  // IP_MULTICAST_LOOP.
      result = Socket::SetMulticastLoop(
          socket,
          protocol,
          DartUtils::GetBooleanValue(Dart_GetNativeArgument(args, 3)));
      break;
    case 2:  // IP_MULTICAST_TTL.
      result = Socket::SetMulticastHops(
          socket,
          protocol,
          DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 3)));
      break;
    case 3: {  // IP_MULTICAST_IF.
      UNIMPLEMENTED();
      break;
    }
    case 4:  // IP_BROADCAST.
      result = Socket::SetBroadcast(
          socket, DartUtils::GetBooleanValue(Dart_GetNativeArgument(args, 3)));
      break;
    default:
      Dart_PropagateError(Dart_NewApiError("Value outside expected range"));
      break;
  }
  if (result) {
    Dart_SetReturnValue(args, Dart_Null());
  } else {
    Dart_SetReturnValue(args, DartUtils::NewDartOSError());
  }
}


void FUNCTION_NAME(Socket_JoinMulticast)(Dart_NativeArguments args) {
  intptr_t socket =
      Socket::GetSocketIdNativeField(Dart_GetNativeArgument(args, 0));
  RawAddr addr;
  SocketAddress::GetSockAddr(Dart_GetNativeArgument(args, 1), &addr);
  RawAddr interface;
  if (Dart_GetNativeArgument(args, 2) != Dart_Null()) {
    SocketAddress::GetSockAddr(Dart_GetNativeArgument(args, 2), &interface);
  }
  int interfaceIndex =
      DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 3));
  if (Socket::JoinMulticast(socket, addr, interface, interfaceIndex)) {
    Dart_SetReturnValue(args, Dart_Null());
  } else {
    Dart_SetReturnValue(args, DartUtils::NewDartOSError());
  }
}


void FUNCTION_NAME(Socket_LeaveMulticast)(Dart_NativeArguments args) {
  intptr_t socket =
      Socket::GetSocketIdNativeField(Dart_GetNativeArgument(args, 0));
  RawAddr addr;
  SocketAddress::GetSockAddr(Dart_GetNativeArgument(args, 1), &addr);
  RawAddr interface;
  if (Dart_GetNativeArgument(args, 2) != Dart_Null()) {
    SocketAddress::GetSockAddr(Dart_GetNativeArgument(args, 2), &interface);
  }
  int interfaceIndex =
      DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 3));
  if (Socket::LeaveMulticast(socket, addr, interface, interfaceIndex)) {
    Dart_SetReturnValue(args, Dart_Null());
  } else {
    Dart_SetReturnValue(args, DartUtils::NewDartOSError());
  }
}


void Socket::SetSocketIdNativeField(Dart_Handle socket, intptr_t id) {
  Dart_Handle err =
      Dart_SetNativeInstanceField(socket, kSocketIdNativeField, id);
  if (Dart_IsError(err)) Dart_PropagateError(err);
}


intptr_t Socket::GetSocketIdNativeField(Dart_Handle socket_obj) {
  intptr_t socket = 0;
  Dart_Handle err =
      Dart_GetNativeInstanceField(socket_obj, kSocketIdNativeField, &socket);
  if (Dart_IsError(err)) Dart_PropagateError(err);
  return socket;
}

}  // namespace bin
}  // namespace dart