/**

 * FreeRDP: A Remote Desktop Protocol Implementation

 * Virtual Channels

 *

 * Copyright 2011 Vic Lee

 * Copyright 2015 Copyright 2015 Thincast Technologies GmbH

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

#include <freerdp/config.h>

#include "settings.h"

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <winpr/crt.h>

#include <winpr/assert.h>

#include <winpr/stream.h>

#include <winpr/wtsapi.h>

#include <freerdp/freerdp.h>

#include <freerdp/constants.h>

#include <freerdp/log.h>

#include <freerdp/svc.h>

#include <freerdp/peer.h>

#include <freerdp/addin.h>

#include <freerdp/client/channels.h>

#include <freerdp/client/drdynvc.h>

#include <freerdp/channels/channels.h>

#include "rdp.h"

#include "client.h"

#include "server.h"

#include "channels.h"

#define TAG FREERDP_TAG("core.channels")

BOOL freerdp_channel_send(rdpRdp* rdp, UINT16 channelId, const BYTE* data, size_t size)

{

  size_t left = 0;

  UINT32 flags = 0;

  size_t chunkSize = 0;

  rdpMcs* mcs = nullptr;

  const rdpMcsChannel* channel = nullptr;

  WINPR_ASSERT(rdp);

  WINPR_ASSERT(data || (size == 0));

  mcs = rdp->mcs;

  WINPR_ASSERT(mcs);

  for (UINT32 i = 0; i < mcs->channelCount; i++)

  {

    const rdpMcsChannel* cur = &mcs->channels[i];

    if (cur->ChannelId == channelId)

    {

      channel = cur;

      break;

    }

  }

  if (!channel)

  {

    WLog_ERR(TAG, "freerdp_channel_send: unknown channelId %" PRIu16 "", channelId);

    return FALSE;

  }

  flags = CHANNEL_FLAG_FIRST;

  left = size;

  const UINT32 VCChunkSize = freerdp_settings_get_uint32(rdp->settings, FreeRDP_VCChunkSize);

  const BOOL ServerMode = freerdp_settings_get_bool(rdp->settings, FreeRDP_ServerMode);

  while (left > 0)

  {

    if (left > VCChunkSize)

    {

      chunkSize = VCChunkSize;

    }

    else

    {

      chunkSize = left;

      flags |= CHANNEL_FLAG_LAST;

    }

    if (!ServerMode && (channel->options & CHANNEL_OPTION_SHOW_PROTOCOL))

    {

      flags |= CHANNEL_FLAG_SHOW_PROTOCOL;

    }

    if (!freerdp_channel_send_packet(rdp, channelId, size, flags, data, chunkSize))

      return FALSE;

    data += chunkSize;

    left -= chunkSize;

    flags = 0;

  }

  return TRUE;

}

BOOL freerdp_channel_process(freerdp* instance, wStream* s, UINT16 channelId, size_t packetLength)

{

  BOOL rc = FALSE;

  UINT32 length = 0;

  UINT32 flags = 0;

  size_t chunkLength = 0;

  WINPR_ASSERT(instance);

  if (packetLength < 8)

  {

    WLog_ERR(TAG, "Header length %" PRIuz " bytes promised, none available", packetLength);

    return FALSE;

  }

  packetLength -= 8;

  if (!Stream_CheckAndLogRequiredLength(TAG, s, 8))

    return FALSE;

  /* [MS-RDPBCGR] 3.1.5.2.2 Processing of Virtual Channel PDU

   * chunked data. Length is the total size of the combined data,

   * chunkLength is the actual data received.

   * check chunkLength against packetLength, which is the TPKT header size.

   */

  Stream_Read_UINT32(s, length);

  Stream_Read_UINT32(s, flags);

  chunkLength = Stream_GetRemainingLength(s);

  if (packetLength != chunkLength)

  {

    WLog_ERR(TAG, "Header length %" PRIuz " != actual length %" PRIuz, packetLength,

             chunkLength);

    return FALSE;

  }

  IFCALLRET(instance->ReceiveChannelData, rc, instance, channelId, Stream_Pointer(s), chunkLength,

            flags, length);

  if (!rc)

  {

    WLog_WARN(TAG, "ReceiveChannelData returned %d", rc);

    return FALSE;

  }

  return Stream_SafeSeek(s, chunkLength);

}

BOOL freerdp_channel_peer_process(freerdp_peer* client, wStream* s, UINT16 channelId)

{

  UINT32 length = 0;

  UINT32 flags = 0;

  WINPR_ASSERT(client);

  WINPR_ASSERT(s);

  if (!Stream_CheckAndLogRequiredLength(TAG, s, 8))

    return FALSE;

  Stream_Read_UINT32(s, length);

  Stream_Read_UINT32(s, flags);

  const size_t chunkLength = Stream_GetRemainingLength(s);

  if (chunkLength > UINT32_MAX)

    return FALSE;

  if (client->VirtualChannelRead)

  {

    int rc = 0;

    BOOL found = FALSE;

    HANDLE hChannel = nullptr;

    rdpContext* context = client->context;

    rdpMcs* mcs = context->rdp->mcs;

    for (UINT32 index = 0; index < mcs->channelCount; index++)

    {

      const rdpMcsChannel* mcsChannel = &(mcs->channels[index]);

      if (mcsChannel->ChannelId == channelId)

      {

        hChannel = (HANDLE)mcsChannel->handle;

        found = TRUE;

        break;

      }

    }

    if (!found)

      return FALSE;

    rc = client->VirtualChannelRead(client, hChannel, Stream_Pointer(s), (UINT32)chunkLength);

    if (rc < 0)

      return FALSE;

  }

  else if (client->ReceiveChannelData)

  {

    BOOL rc = client->ReceiveChannelData(client, channelId, Stream_Pointer(s),

                                         (UINT32)chunkLength, flags, length);

    if (!rc)

      return FALSE;

  }

  if (!Stream_SafeSeek(s, chunkLength))

  {

    WLog_WARN(TAG, "Short PDU, need %" PRIuz " bytes, got %" PRIuz, chunkLength,

              Stream_GetRemainingLength(s));

    return FALSE;

  }

  return TRUE;

}

static const WtsApiFunctionTable FreeRDP_WtsApiFunctionTable = {

  0, /* dwVersion */

  0, /* dwFlags */

  FreeRDP_WTSStopRemoteControlSession,        /* StopRemoteControlSession */

  FreeRDP_WTSStartRemoteControlSessionW,      /* StartRemoteControlSessionW */

  FreeRDP_WTSStartRemoteControlSessionA,      /* StartRemoteControlSessionA */

  FreeRDP_WTSConnectSessionW,                 /* ConnectSessionW */

  FreeRDP_WTSConnectSessionA,                 /* ConnectSessionA */

  FreeRDP_WTSEnumerateServersW,               /* EnumerateServersW */

  FreeRDP_WTSEnumerateServersA,               /* EnumerateServersA */

  FreeRDP_WTSOpenServerW,                     /* OpenServerW */

  FreeRDP_WTSOpenServerA,                     /* OpenServerA */

  FreeRDP_WTSOpenServerExW,                   /* OpenServerExW */

  FreeRDP_WTSOpenServerExA,                   /* OpenServerExA */

  FreeRDP_WTSCloseServer,                     /* CloseServer */

  FreeRDP_WTSEnumerateSessionsW,              /* EnumerateSessionsW */

  FreeRDP_WTSEnumerateSessionsA,              /* EnumerateSessionsA */

  FreeRDP_WTSEnumerateSessionsExW,            /* EnumerateSessionsExW */

  FreeRDP_WTSEnumerateSessionsExA,            /* EnumerateSessionsExA */

  FreeRDP_WTSEnumerateProcessesW,             /* EnumerateProcessesW */

  FreeRDP_WTSEnumerateProcessesA,             /* EnumerateProcessesA */

  FreeRDP_WTSTerminateProcess,                /* TerminateProcess */

  FreeRDP_WTSQuerySessionInformationW,        /* QuerySessionInformationW */

  FreeRDP_WTSQuerySessionInformationA,        /* QuerySessionInformationA */

  FreeRDP_WTSQueryUserConfigW,                /* QueryUserConfigW */

  FreeRDP_WTSQueryUserConfigA,                /* QueryUserConfigA */

  FreeRDP_WTSSetUserConfigW,                  /* SetUserConfigW */

  FreeRDP_WTSSetUserConfigA,                  /* SetUserConfigA */

  FreeRDP_WTSSendMessageW,                    /* SendMessageW */

  FreeRDP_WTSSendMessageA,                    /* SendMessageA */

  FreeRDP_WTSDisconnectSession,               /* DisconnectSession */

  FreeRDP_WTSLogoffSession,                   /* LogoffSession */

  FreeRDP_WTSShutdownSystem,                  /* ShutdownSystem */

  FreeRDP_WTSWaitSystemEvent,                 /* WaitSystemEvent */

  FreeRDP_WTSVirtualChannelOpen,              /* VirtualChannelOpen */

  FreeRDP_WTSVirtualChannelOpenEx,            /* VirtualChannelOpenEx */

  FreeRDP_WTSVirtualChannelClose,             /* VirtualChannelClose */

  FreeRDP_WTSVirtualChannelRead,              /* VirtualChannelRead */

  FreeRDP_WTSVirtualChannelWrite,             /* VirtualChannelWrite */

  FreeRDP_WTSVirtualChannelPurgeInput,        /* VirtualChannelPurgeInput */

  FreeRDP_WTSVirtualChannelPurgeOutput,       /* VirtualChannelPurgeOutput */

  FreeRDP_WTSVirtualChannelQuery,             /* VirtualChannelQuery */

  FreeRDP_WTSFreeMemory,                      /* FreeMemory */

  FreeRDP_WTSRegisterSessionNotification,     /* RegisterSessionNotification */

  FreeRDP_WTSUnRegisterSessionNotification,   /* UnRegisterSessionNotification */

  FreeRDP_WTSRegisterSessionNotificationEx,   /* RegisterSessionNotificationEx */

  FreeRDP_WTSUnRegisterSessionNotificationEx, /* UnRegisterSessionNotificationEx */

  FreeRDP_WTSQueryUserToken,                  /* QueryUserToken */

  FreeRDP_WTSFreeMemoryExW,                   /* FreeMemoryExW */

  FreeRDP_WTSFreeMemoryExA,                   /* FreeMemoryExA */

  FreeRDP_WTSEnumerateProcessesExW,           /* EnumerateProcessesExW */

  FreeRDP_WTSEnumerateProcessesExA,           /* EnumerateProcessesExA */

  FreeRDP_WTSEnumerateListenersW,             /* EnumerateListenersW */

  FreeRDP_WTSEnumerateListenersA,             /* EnumerateListenersA */

  FreeRDP_WTSQueryListenerConfigW,            /* QueryListenerConfigW */

  FreeRDP_WTSQueryListenerConfigA,            /* QueryListenerConfigA */

  FreeRDP_WTSCreateListenerW,                 /* CreateListenerW */

  FreeRDP_WTSCreateListenerA,                 /* CreateListenerA */

  FreeRDP_WTSSetListenerSecurityW,            /* SetListenerSecurityW */

  FreeRDP_WTSSetListenerSecurityA,            /* SetListenerSecurityA */

  FreeRDP_WTSGetListenerSecurityW,            /* GetListenerSecurityW */

  FreeRDP_WTSGetListenerSecurityA,            /* GetListenerSecurityA */

  FreeRDP_WTSEnableChildSessions,             /* EnableChildSessions */

  FreeRDP_WTSIsChildSessionsEnabled,          /* IsChildSessionsEnabled */

  FreeRDP_WTSGetChildSessionId,               /* GetChildSessionId */

  FreeRDP_WTSGetActiveConsoleSessionId,       /* GetActiveConsoleSessionId */

  FreeRDP_WTSLogonUser,

  FreeRDP_WTSLogoffUser,

  FreeRDP_WTSStartRemoteControlSessionExW,

  FreeRDP_WTSStartRemoteControlSessionExA

};

const WtsApiFunctionTable* FreeRDP_InitWtsApi(void)

{

  return &FreeRDP_WtsApiFunctionTable;

}

BOOL freerdp_channel_send_packet(rdpRdp* rdp, UINT16 channelId, size_t totalSize, UINT32 flags,

                                 const BYTE* data, size_t chunkSize)

{

  if (totalSize > UINT32_MAX)

    return FALSE;

  UINT16 sec_flags = 0;

  wStream* s = rdp_send_stream_init(rdp, &sec_flags);

  if (!s)

    return FALSE;

  if (!Stream_EnsureRemainingCapacity(s, chunkSize + 8))

  {

    Stream_Release(s);

    return FALSE;

  }

  Stream_Write_UINT32(s, (UINT32)totalSize);

  Stream_Write_UINT32(s, flags);

  Stream_Write(s, data, chunkSize);

  /* WLog_DBG(TAG, "sending data (flags=0x%x size=%d)",  flags, size); */

  return rdp_send(rdp, s, channelId, sec_flags);

}