gfxredir_main.c

 
#include <freerdp/config.h>
 
#include "gfxredir_main.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
 
#include <winpr/crt.h>
#include <winpr/assert.h>
#include <winpr/synch.h>
#include <winpr/thread.h>
#include <winpr/stream.h>
#include <winpr/sysinfo.h>
#include <freerdp/channels/wtsvc.h>
#include <freerdp/channels/log.h>
 
#include <freerdp/server/gfxredir.h>
#include <gfxredir_common.h>
 
#define TAG CHANNELS_TAG("gfxredir.server")
 
static UINT gfxredir_recv_legacy_caps_pdu(wStream* s, GfxRedirServerContext* context)
{
  UINT32 error = CHANNEL_RC_OK;
  GFXREDIR_LEGACY_CAPS_PDU pdu = WINPR_C_ARRAY_INIT;
 
  WINPR_ASSERT(context);
 
  if (!Stream_CheckAndLogRequiredLength(TAG, s, 2))
    return ERROR_INVALID_DATA;
 
  Stream_Read_UINT16(s, pdu.version); /* version (2 bytes) */
 
  if (context)
    IFCALLRET(context->GraphicsRedirectionLegacyCaps, error, context, &pdu);
 
  return error;
}
 
static UINT gfxredir_recv_caps_advertise_pdu(wStream* s, UINT32 length,
                                             GfxRedirServerContext* context)
{
  UINT32 error = CHANNEL_RC_OK;
  GFXREDIR_CAPS_ADVERTISE_PDU pdu = WINPR_C_ARRAY_INIT;
 
  WINPR_ASSERT(context);
 
  if (!Stream_CheckAndLogRequiredLength(TAG, s, length))
    return ERROR_INVALID_DATA;
 
  pdu.length = length;
  Stream_GetPointer(s, pdu.caps);
  Stream_Seek(s, length);
 
  if (!context->GraphicsRedirectionCapsAdvertise)
  {
    WLog_ERR(TAG, "server does not support CapsAdvertise PDU!");
    return ERROR_NOT_SUPPORTED;
  }
  else if (context)
  {
    IFCALLRET(context->GraphicsRedirectionCapsAdvertise, error, context, &pdu);
  }
 
  return error;
}
 
static UINT gfxredir_recv_present_buffer_ack_pdu(wStream* s, GfxRedirServerContext* context)
{
  UINT32 error = CHANNEL_RC_OK;
  GFXREDIR_PRESENT_BUFFER_ACK_PDU pdu = WINPR_C_ARRAY_INIT;
 
  WINPR_ASSERT(context);
 
  if (!Stream_CheckAndLogRequiredLength(TAG, s, 16))
    return ERROR_INVALID_DATA;
 
  Stream_Read_UINT64(s, pdu.windowId);  /* windowId (8 bytes) */
  Stream_Read_UINT64(s, pdu.presentId); /* presentId (8 bytes) */
 
  if (context)
  {
    IFCALLRET(context->PresentBufferAck, error, context, &pdu);
  }
 
  return error;
}
 
static UINT gfxredir_server_receive_pdu(GfxRedirServerContext* context, wStream* data)
{
  UINT error = CHANNEL_RC_OK;
  GFXREDIR_HEADER header = WINPR_C_ARRAY_INIT;
 
  WINPR_ASSERT(context);
 
  size_t packetLen = 0;
  if ((error = gfxredir_read_header(data, &header, &packetLen)))
  {
    WLog_ERR(TAG, "gfxredir_read_header failed with error %" PRIu32 "!", error);
    return error;
  }
 
  wStream sbuffer = WINPR_C_ARRAY_INIT;
  wStream* s = Stream_StaticConstInit(&sbuffer, Stream_ConstPointer(data), packetLen);
  Stream_Seek(data, packetLen);
 
  switch (header.cmdId)
  {
    case GFXREDIR_CMDID_LEGACY_CAPS:
      if ((error = gfxredir_recv_legacy_caps_pdu(s, context)))
        WLog_ERR(TAG,
                 "gfxredir_recv_legacy_caps_pdu "
                 "failed with error %" PRIu32 "!",
                 error);
 
      break;
 
    case GFXREDIR_CMDID_CAPS_ADVERTISE:
      if ((error = gfxredir_recv_caps_advertise_pdu(s, header.length - 8, context)))
        WLog_ERR(TAG,
                 "gfxredir_recv_caps_advertise "
                 "failed with error %" PRIu32 "!",
                 error);
      break;
 
    case GFXREDIR_CMDID_PRESENT_BUFFER_ACK:
      if ((error = gfxredir_recv_present_buffer_ack_pdu(s, context)))
        WLog_ERR(TAG,
                 "gfxredir_recv_present_buffer_ask_pdu "
                 "failed with error %" PRIu32 "!",
                 error);
      break;
 
    default:
      error = CHANNEL_RC_BAD_PROC;
      WLog_WARN(TAG, "Received unknown PDU type: %" PRIu32 "", header.cmdId);
      break;
  }
 
  const size_t end = Stream_GetPosition(s);
 
  if (end != packetLen)
  {
    WLog_ERR(TAG, "Unexpected GFXREDIR pdu end: Actual: %" PRIuz ", Expected: %" PRIuz "", end,
             packetLen);
  }
 
  return error;
}
 
static UINT gfxredir_server_handle_messages(GfxRedirServerContext* context)
{
  UINT ret = CHANNEL_RC_OK;
 
  WINPR_ASSERT(context);
 
  GfxRedirServerPrivate* priv = context->priv;
  WINPR_ASSERT(priv);
 
  wStream* s = priv->input_stream;
 
  /* Check whether the dynamic channel is ready */
  if (!priv->isReady)
  {
    void* buffer = nullptr;
    DWORD BytesReturned = 0;
    if (WTSVirtualChannelQuery(priv->gfxredir_channel, WTSVirtualChannelReady, &buffer,
                               &BytesReturned) == FALSE)
    {
      if (GetLastError() == ERROR_NO_DATA)
        return ERROR_NO_DATA;
 
      WLog_ERR(TAG, "WTSVirtualChannelQuery failed");
      return ERROR_INTERNAL_ERROR;
    }
 
    priv->isReady = *((BOOL*)buffer);
    WTSFreeMemory(buffer);
  }
 
  /* Consume channel event only after the dynamic channel is ready */
  if (priv->isReady)
  {
    Stream_ResetPosition(s);
 
    DWORD BytesReturned = 0;
    if (!WTSVirtualChannelRead(priv->gfxredir_channel, 0, nullptr, 0, &BytesReturned))
    {
      if (GetLastError() == ERROR_NO_DATA)
        return ERROR_NO_DATA;
 
      WLog_ERR(TAG, "WTSVirtualChannelRead failed!");
      return ERROR_INTERNAL_ERROR;
    }
 
    if (BytesReturned < 1)
      return CHANNEL_RC_OK;
 
    if (!Stream_EnsureRemainingCapacity(s, BytesReturned))
    {
      WLog_ERR(TAG, "Stream_EnsureRemainingCapacity failed!");
      return CHANNEL_RC_NO_MEMORY;
    }
 
    const ULONG cap = WINPR_ASSERTING_INT_CAST(ULONG, Stream_Capacity(s));
    if (WTSVirtualChannelRead(priv->gfxredir_channel, 0, (PCHAR)Stream_Buffer(s), cap,
                              &BytesReturned) == FALSE)
    {
      WLog_ERR(TAG, "WTSVirtualChannelRead failed!");
      return ERROR_INTERNAL_ERROR;
    }
 
    if (!Stream_SetLength(s, BytesReturned))
      return ERROR_INTERNAL_ERROR;
 
    Stream_ResetPosition(s);
 
    while (Stream_GetPosition(s) < Stream_Length(s))
    {
      if ((ret = gfxredir_server_receive_pdu(context, s)))
      {
        WLog_ERR(TAG,
                 "gfxredir_server_receive_pdu "
                 "failed with error %" PRIu32 "!",
                 ret);
        return ret;
      }
    }
  }
 
  return ret;
}
 
static DWORD WINAPI gfxredir_server_thread_func(LPVOID arg)
{
  GfxRedirServerContext* context = (GfxRedirServerContext*)arg;
  WINPR_ASSERT(context);
 
  GfxRedirServerPrivate* priv = context->priv;
  WINPR_ASSERT(priv);
 
  HANDLE events[8] = WINPR_C_ARRAY_INIT;
  UINT error = CHANNEL_RC_OK;
  DWORD nCount = 0;
  events[nCount++] = priv->stopEvent;
  events[nCount++] = priv->channelEvent;
 
  while (TRUE)
  {
    const DWORD status = WaitForMultipleObjects(nCount, events, FALSE, INFINITE);
 
    if (status == WAIT_FAILED)
    {
      error = GetLastError();
      WLog_ERR(TAG, "WaitForMultipleObjects failed with error %" PRIu32 "", error);
      break;
    }
 
    /* Stop Event */
    if (status == WAIT_OBJECT_0)
      break;
 
    if ((error = gfxredir_server_handle_messages(context)))
    {
      WLog_ERR(TAG, "gfxredir_server_handle_messages failed with error %" PRIu32 "", error);
      break;
    }
  }
 
  ExitThread(error);
  return error;
}
 
static wStream* gfxredir_server_single_packet_new(UINT32 cmdId, size_t length)
{
  GFXREDIR_HEADER header = WINPR_C_ARRAY_INIT;
  wStream* s = Stream_New(nullptr, GFXREDIR_HEADER_SIZE + length);
 
  if (!s)
  {
    WLog_ERR(TAG, "Stream_New failed!");
    goto error;
  }
 
  header.cmdId = cmdId;
  header.length = WINPR_ASSERTING_INT_CAST(UINT32, GFXREDIR_HEADER_SIZE + length);
 
  const UINT error = gfxredir_write_header(s, &header);
  if (error)
  {
    WLog_ERR(TAG, "Failed to write header with error %" PRIu32 "!", error);
    goto error;
  }
 
  return s;
error:
  Stream_Free(s, TRUE);
  return nullptr;
}
 
static UINT gfxredir_server_packet_send(GfxRedirServerContext* context, wStream* s)
{
  UINT ret = ERROR_INTERNAL_ERROR;
  ULONG written = 0;
 
  WINPR_ASSERT(context);
 
  const ULONG cap = WINPR_ASSERTING_INT_CAST(ULONG, Stream_GetPosition(s));
  if (!WTSVirtualChannelWrite(context->priv->gfxredir_channel, (PCHAR)Stream_Buffer(s), cap,
                              &written))
  {
    WLog_ERR(TAG, "WTSVirtualChannelWrite failed!");
    ret = ERROR_INTERNAL_ERROR;
    goto out;
  }
 
  if (written < Stream_GetPosition(s))
  {
    WLog_WARN(TAG, "Unexpected bytes written: %" PRIu32 "/%" PRIuz "", written,
              Stream_GetPosition(s));
  }
 
  ret = CHANNEL_RC_OK;
out:
  Stream_Free(s, TRUE);
  return ret;
}
 
static UINT gfxredir_send_error(GfxRedirServerContext* context, const GFXREDIR_ERROR_PDU* error)
{
  WINPR_ASSERT(context);
  WINPR_ASSERT(error);
 
  wStream* s = gfxredir_server_single_packet_new(GFXREDIR_CMDID_ERROR, 4);
 
  if (!s)
  {
    WLog_ERR(TAG, "gfxredir_server_single_packet_new failed!");
    return CHANNEL_RC_NO_MEMORY;
  }
 
  Stream_Write_UINT32(s, error->errorCode);
  return gfxredir_server_packet_send(context, s);
}
 
static UINT gfxredir_send_caps_confirm(GfxRedirServerContext* context,
                                       const GFXREDIR_CAPS_CONFIRM_PDU* graphicsCapsConfirm)
{
  WINPR_ASSERT(context);
  WINPR_ASSERT(graphicsCapsConfirm);
 
  if (graphicsCapsConfirm->length < GFXREDIR_CAPS_HEADER_SIZE)
  {
    WLog_ERR(TAG, "length must be greater than header size, failed!");
    return ERROR_INVALID_DATA;
  }
 
  wStream* s =
      gfxredir_server_single_packet_new(GFXREDIR_CMDID_CAPS_CONFIRM, graphicsCapsConfirm->length);
 
  if (!s)
  {
    WLog_ERR(TAG, "gfxredir_server_single_packet_new failed!");
    return CHANNEL_RC_NO_MEMORY;
  }
 
  Stream_Write_UINT32(s, GFXREDIR_CAPS_SIGNATURE);
  Stream_Write_UINT32(s, graphicsCapsConfirm->version);
  Stream_Write_UINT32(s, graphicsCapsConfirm->length);
  if (graphicsCapsConfirm->length > GFXREDIR_CAPS_HEADER_SIZE)
    Stream_Write(s, graphicsCapsConfirm->capsData,
                 graphicsCapsConfirm->length - GFXREDIR_CAPS_HEADER_SIZE);
  const UINT ret = gfxredir_server_packet_send(context, s);
  if (ret == CHANNEL_RC_OK)
    context->confirmedCapsVersion = graphicsCapsConfirm->version;
  return ret;
}
 
static UINT gfxredir_send_open_pool(GfxRedirServerContext* context,
                                    const GFXREDIR_OPEN_POOL_PDU* openPool)
{
  WINPR_ASSERT(context);
  WINPR_ASSERT(openPool);
 
  if (context->confirmedCapsVersion != GFXREDIR_CAPS_VERSION2_0)
  {
    WLog_ERR(TAG, "open_pool is called with invalid version!");
    return ERROR_INTERNAL_ERROR;
  }
 
  if (openPool->sectionNameLength == 0 || openPool->sectionName == nullptr)
  {
    WLog_ERR(TAG, "section name must be provided!");
    return ERROR_INVALID_DATA;
  }
 
  /* make sure null-terminate */
  if (openPool->sectionName[openPool->sectionNameLength - 1] != 0)
  {
    WLog_ERR(TAG, "section name must be terminated with nullptr!");
    return ERROR_INVALID_DATA;
  }
 
  wStream* s = gfxredir_server_single_packet_new(GFXREDIR_CMDID_OPEN_POOL,
                                                 20 + (openPool->sectionNameLength * 2));
 
  if (!s)
  {
    WLog_ERR(TAG, "gfxredir_server_single_packet_new failed!");
    return CHANNEL_RC_NO_MEMORY;
  }
 
  Stream_Write_UINT64(s, openPool->poolId);
  Stream_Write_UINT64(s, openPool->poolSize);
  Stream_Write_UINT32(s, openPool->sectionNameLength);
  Stream_Write(s, openPool->sectionName, (2ULL * openPool->sectionNameLength));
  return gfxredir_server_packet_send(context, s);
}
 
static UINT gfxredir_send_close_pool(GfxRedirServerContext* context,
                                     const GFXREDIR_CLOSE_POOL_PDU* closePool)
{
  WINPR_ASSERT(context);
  WINPR_ASSERT(closePool);
 
  if (context->confirmedCapsVersion != GFXREDIR_CAPS_VERSION2_0)
  {
    WLog_ERR(TAG, "close_pool is called with invalid version!");
    return ERROR_INTERNAL_ERROR;
  }
 
  wStream* s = gfxredir_server_single_packet_new(GFXREDIR_CMDID_CLOSE_POOL, 8);
 
  if (!s)
  {
    WLog_ERR(TAG, "gfxredir_server_single_packet_new failed!");
    return CHANNEL_RC_NO_MEMORY;
  }
 
  Stream_Write_UINT64(s, closePool->poolId);
  return gfxredir_server_packet_send(context, s);
}
 
static UINT gfxredir_send_create_buffer(GfxRedirServerContext* context,
                                        const GFXREDIR_CREATE_BUFFER_PDU* createBuffer)
{
  WINPR_ASSERT(context);
  WINPR_ASSERT(createBuffer);
 
  if (context->confirmedCapsVersion != GFXREDIR_CAPS_VERSION2_0)
  {
    WLog_ERR(TAG, "create_buffer is called with invalid version!");
    return ERROR_INTERNAL_ERROR;
  }
 
  wStream* s = gfxredir_server_single_packet_new(GFXREDIR_CMDID_CREATE_BUFFER, 40);
 
  if (!s)
  {
    WLog_ERR(TAG, "gfxredir_server_single_packet_new failed!");
    return CHANNEL_RC_NO_MEMORY;
  }
 
  Stream_Write_UINT64(s, createBuffer->poolId);
  Stream_Write_UINT64(s, createBuffer->bufferId);
  Stream_Write_UINT64(s, createBuffer->offset);
  Stream_Write_UINT32(s, createBuffer->stride);
  Stream_Write_UINT32(s, createBuffer->width);
  Stream_Write_UINT32(s, createBuffer->height);
  Stream_Write_UINT32(s, createBuffer->format);
  return gfxredir_server_packet_send(context, s);
}
 
static UINT gfxredir_send_destroy_buffer(GfxRedirServerContext* context,
                                         const GFXREDIR_DESTROY_BUFFER_PDU* destroyBuffer)
{
  WINPR_ASSERT(context);
  WINPR_ASSERT(destroyBuffer);
 
  if (context->confirmedCapsVersion != GFXREDIR_CAPS_VERSION2_0)
  {
    WLog_ERR(TAG, "destroy_buffer is called with invalid version!");
    return ERROR_INTERNAL_ERROR;
  }
 
  wStream* s = gfxredir_server_single_packet_new(GFXREDIR_CMDID_DESTROY_BUFFER, 8);
 
  if (!s)
  {
    WLog_ERR(TAG, "gfxredir_server_single_packet_new failed!");
    return CHANNEL_RC_NO_MEMORY;
  }
 
  Stream_Write_UINT64(s, destroyBuffer->bufferId);
  return gfxredir_server_packet_send(context, s);
}
 
static UINT gfxredir_send_present_buffer(GfxRedirServerContext* context,
                                         const GFXREDIR_PRESENT_BUFFER_PDU* presentBuffer)
{
  RECTANGLE_32 dummyRect = { 0, 0, 0, 0 };
 
  WINPR_ASSERT(context);
  WINPR_ASSERT(presentBuffer);
 
  if (context->confirmedCapsVersion != GFXREDIR_CAPS_VERSION2_0)
  {
    WLog_ERR(TAG, "present_buffer is called with invalid version!");
    return ERROR_INTERNAL_ERROR;
  }
 
  if (presentBuffer->numOpaqueRects > GFXREDIR_MAX_OPAQUE_RECTS)
  {
    WLog_ERR(TAG, "numOpaqueRects is larger than its limit!");
    return ERROR_INVALID_DATA;
  }
 
  const size_t length =
      64ULL + ((presentBuffer->numOpaqueRects ? presentBuffer->numOpaqueRects : 1) *
               sizeof(RECTANGLE_32));
 
  wStream* s = gfxredir_server_single_packet_new(GFXREDIR_CMDID_PRESENT_BUFFER, length);
 
  if (!s)
  {
    WLog_ERR(TAG, "gfxredir_server_single_packet_new failed!");
    return CHANNEL_RC_NO_MEMORY;
  }
 
  Stream_Write_UINT64(s, presentBuffer->timestamp);
  Stream_Write_UINT64(s, presentBuffer->presentId);
  Stream_Write_UINT64(s, presentBuffer->windowId);
  Stream_Write_UINT64(s, presentBuffer->bufferId);
  Stream_Write_UINT32(s, presentBuffer->orientation);
  Stream_Write_UINT32(s, presentBuffer->targetWidth);
  Stream_Write_UINT32(s, presentBuffer->targetHeight);
  Stream_Write_UINT32(s, presentBuffer->dirtyRect.left);
  Stream_Write_UINT32(s, presentBuffer->dirtyRect.top);
  Stream_Write_UINT32(s, presentBuffer->dirtyRect.width);
  Stream_Write_UINT32(s, presentBuffer->dirtyRect.height);
  Stream_Write_UINT32(s, presentBuffer->numOpaqueRects);
  if (presentBuffer->numOpaqueRects)
    Stream_Write(s, presentBuffer->opaqueRects,
                 (presentBuffer->numOpaqueRects * sizeof(RECTANGLE_32)));
  else
    Stream_Write(s, &dummyRect, sizeof(RECTANGLE_32));
  return gfxredir_server_packet_send(context, s);
}
 
static UINT gfxredir_server_open(GfxRedirServerContext* context)
{
  UINT rc = ERROR_INTERNAL_ERROR;
  WINPR_ASSERT(context);
 
  GfxRedirServerPrivate* priv = context->priv;
  WINPR_ASSERT(priv);
 
  DWORD BytesReturned = 0;
  PULONG pSessionId = nullptr;
  void* buffer = nullptr;
  priv->SessionId = WTS_CURRENT_SESSION;
 
  if (WTSQuerySessionInformationA(context->vcm, WTS_CURRENT_SESSION, WTSSessionId,
                                  (LPSTR*)&pSessionId, &BytesReturned) == FALSE)
  {
    WLog_ERR(TAG, "WTSQuerySessionInformationA failed!");
    rc = ERROR_INTERNAL_ERROR;
    goto out_close;
  }
 
  priv->SessionId = (DWORD)*pSessionId;
  WTSFreeMemory(pSessionId);
  priv->gfxredir_channel = WTSVirtualChannelOpenEx(priv->SessionId, GFXREDIR_DVC_CHANNEL_NAME,
                                                   WTS_CHANNEL_OPTION_DYNAMIC);
 
  if (!priv->gfxredir_channel)
  {
    WLog_ERR(TAG, "WTSVirtualChannelOpenEx failed!");
    rc = GetLastError();
    goto out_close;
  }
 
  /* Query for channel event handle */
  if (!WTSVirtualChannelQuery(priv->gfxredir_channel, WTSVirtualEventHandle, &buffer,
                              &BytesReturned) ||
      (BytesReturned != sizeof(HANDLE)))
  {
    WLog_ERR(TAG,
             "WTSVirtualChannelQuery failed "
             "or invalid returned size(%" PRIu32 ")",
             BytesReturned);
 
    if (buffer)
      WTSFreeMemory(buffer);
 
    rc = ERROR_INTERNAL_ERROR;
    goto out_close;
  }
 
  priv->channelEvent = *(HANDLE*)buffer;
  WTSFreeMemory(buffer);
 
  if (priv->thread == nullptr)
  {
    if (!(priv->stopEvent = CreateEvent(nullptr, TRUE, FALSE, nullptr)))
    {
      WLog_ERR(TAG, "CreateEvent failed!");
      goto out_close;
    }
 
    if (!(priv->thread = CreateThread(nullptr, 0, gfxredir_server_thread_func, (void*)context,
                                      0, nullptr)))
    {
      WLog_ERR(TAG, "CreateEvent failed!");
      (void)CloseHandle(priv->stopEvent);
      priv->stopEvent = nullptr;
      goto out_close;
    }
  }
 
  return CHANNEL_RC_OK;
out_close:
  WTSVirtualChannelClose(priv->gfxredir_channel);
  priv->gfxredir_channel = nullptr;
  priv->channelEvent = nullptr;
  return rc;
}
 
static UINT gfxredir_server_close(GfxRedirServerContext* context)
{
  UINT error = CHANNEL_RC_OK;
  WINPR_ASSERT(context);
 
  GfxRedirServerPrivate* priv = context->priv;
  WINPR_ASSERT(priv);
 
  if (priv->thread)
  {
    (void)SetEvent(priv->stopEvent);
 
    if (WaitForSingleObject(priv->thread, INFINITE) == WAIT_FAILED)
    {
      error = GetLastError();
      WLog_ERR(TAG, "WaitForSingleObject failed with error %" PRIu32 "", error);
      return error;
    }
 
    (void)CloseHandle(priv->thread);
    (void)CloseHandle(priv->stopEvent);
    priv->thread = nullptr;
    priv->stopEvent = nullptr;
  }
 
  if (priv->gfxredir_channel)
  {
    WTSVirtualChannelClose(priv->gfxredir_channel);
    priv->gfxredir_channel = nullptr;
  }
 
  return error;
}
 
GfxRedirServerContext* gfxredir_server_context_new(HANDLE vcm)
{
  GfxRedirServerContext* context =
      (GfxRedirServerContext*)calloc(1, sizeof(GfxRedirServerContext));
 
  if (!context)
  {
    WLog_ERR(TAG, "gfxredir_server_context_new(): calloc GfxRedirServerContext failed!");
    return nullptr;
  }
 
  GfxRedirServerPrivate* priv = context->priv =
      (GfxRedirServerPrivate*)calloc(1, sizeof(GfxRedirServerPrivate));
 
  if (!context->priv)
  {
    WLog_ERR(TAG, "gfxredir_server_context_new(): calloc GfxRedirServerPrivate failed!");
    goto fail;
  }
 
  priv->input_stream = Stream_New(nullptr, 4);
 
  if (!priv->input_stream)
  {
    WLog_ERR(TAG, "Stream_New failed!");
    goto fail;
  }
 
  context->vcm = vcm;
  context->Open = gfxredir_server_open;
  context->Close = gfxredir_server_close;
  context->Error = gfxredir_send_error;
  context->GraphicsRedirectionCapsConfirm = gfxredir_send_caps_confirm;
  context->OpenPool = gfxredir_send_open_pool;
  context->ClosePool = gfxredir_send_close_pool;
  context->CreateBuffer = gfxredir_send_create_buffer;
  context->DestroyBuffer = gfxredir_send_destroy_buffer;
  context->PresentBuffer = gfxredir_send_present_buffer;
  context->confirmedCapsVersion = GFXREDIR_CAPS_VERSION1;
  priv->isReady = FALSE;
  return context;
fail:
  gfxredir_server_context_free(context);
  return nullptr;
}
 
void gfxredir_server_context_free(GfxRedirServerContext* context)
{
  if (!context)
    return;
 
  gfxredir_server_close(context);
 
  if (context->priv)
  {
    Stream_Free(context->priv->input_stream, TRUE);
    free(context->priv);
  }
 
  free(context);
}