FreeRDP/channels/rdpdr/server/rdpdr_main.c
Hardening c076ffb020 Don't use NULL for pWrittenBytes when calling WTSVirtualChannelWrite()
Nothing in the MSDN API says that setting NULL is safe. And if the
implementation uses WriteFile directly, it crashes.
2014-05-28 17:04:24 +02:00

704 lines
19 KiB
C

/**
* FreeRDP: A Remote Desktop Protocol Implementation
* Device Redirection Virtual Channel Extension
*
* Copyright 2013 Marc-Andre Moreau <marcandre.moreau@gmail.com>
*
* 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <winpr/crt.h>
#include <winpr/print.h>
#include <winpr/stream.h>
#include "rdpdr_main.h"
static UINT32 g_ClientId = 0;
static int rdpdr_server_send_announce_request(RdpdrServerContext* context)
{
wStream* s;
BOOL status;
RDPDR_HEADER header;
ULONG written;
printf("RdpdrServerSendAnnounceRequest\n");
header.Component = RDPDR_CTYP_CORE;
header.PacketId = PAKID_CORE_SERVER_ANNOUNCE;
s = Stream_New(NULL, RDPDR_HEADER_LENGTH + 8);
Stream_Write_UINT16(s, header.Component); /* Component (2 bytes) */
Stream_Write_UINT16(s, header.PacketId); /* PacketId (2 bytes) */
Stream_Write_UINT16(s, context->priv->VersionMajor); /* VersionMajor (2 bytes) */
Stream_Write_UINT16(s, context->priv->VersionMinor); /* VersionMinor (2 bytes) */
Stream_Write_UINT32(s, context->priv->ClientId); /* ClientId (4 bytes) */
Stream_SealLength(s);
status = WTSVirtualChannelWrite(context->priv->ChannelHandle, (PCHAR) Stream_Buffer(s), Stream_Length(s), &written);
Stream_Free(s, TRUE);
return 0;
}
static int rdpdr_server_receive_announce_response(RdpdrServerContext* context, wStream* s, RDPDR_HEADER* header)
{
UINT32 ClientId;
UINT16 VersionMajor;
UINT16 VersionMinor;
Stream_Read_UINT16(s, VersionMajor); /* VersionMajor (2 bytes) */
Stream_Read_UINT16(s, VersionMinor); /* VersionMinor (2 bytes) */
Stream_Read_UINT32(s, ClientId); /* ClientId (4 bytes) */
printf("Client Announce Response: VersionMajor: 0x%04X VersionMinor: 0x%04X ClientId: 0x%04X\n",
VersionMajor, VersionMinor, ClientId);
context->priv->ClientId = ClientId;
return 0;
}
static int rdpdr_server_receive_client_name_request(RdpdrServerContext* context, wStream* s, RDPDR_HEADER* header)
{
UINT32 UnicodeFlag;
UINT32 ComputerNameLen;
Stream_Read_UINT32(s, UnicodeFlag); /* UnicodeFlag (4 bytes) */
Stream_Seek_UINT32(s); /* CodePage (4 bytes), MUST be set to zero */
Stream_Read_UINT32(s, ComputerNameLen); /* ComputerNameLen (4 bytes) */
/**
* Caution: ComputerNameLen is given *bytes*,
* not in characters, including the NULL terminator!
*/
if (context->priv->ClientComputerName)
{
free(context->priv->ClientComputerName);
context->priv->ClientComputerName = NULL;
}
if (UnicodeFlag)
{
ConvertFromUnicode(CP_UTF8, 0, (WCHAR*) Stream_Pointer(s),
-1, &(context->priv->ClientComputerName), 0, NULL, NULL);
}
else
{
context->priv->ClientComputerName = _strdup((char*) Stream_Pointer(s));
}
Stream_Seek(s, ComputerNameLen);
printf("ClientComputerName: %s\n", context->priv->ClientComputerName);
return 0;
}
static int rdpdr_server_read_capability_set_header(wStream* s, RDPDR_CAPABILITY_HEADER* header)
{
Stream_Read_UINT16(s, header->CapabilityType); /* CapabilityType (2 bytes) */
Stream_Read_UINT16(s, header->CapabilityLength); /* CapabilityLength (2 bytes) */
Stream_Read_UINT32(s, header->Version); /* Version (4 bytes) */
return 0;
}
static int rdpdr_server_write_capability_set_header(wStream* s, RDPDR_CAPABILITY_HEADER* header)
{
Stream_Write_UINT16(s, header->CapabilityType); /* CapabilityType (2 bytes) */
Stream_Write_UINT16(s, header->CapabilityLength); /* CapabilityLength (2 bytes) */
Stream_Write_UINT32(s, header->Version); /* Version (4 bytes) */
return 0;
}
static int rdpdr_server_read_general_capability_set(RdpdrServerContext* context, wStream* s, RDPDR_CAPABILITY_HEADER* header)
{
UINT32 ioCode1;
UINT32 extraFlags1;
UINT32 extendedPdu;
UINT16 VersionMajor;
UINT16 VersionMinor;
UINT32 SpecialTypeDeviceCap;
Stream_Seek_UINT32(s); /* osType (4 bytes), ignored on receipt */
Stream_Seek_UINT32(s); /* osVersion (4 bytes), unused and must be set to zero */
Stream_Read_UINT16(s, VersionMajor); /* protocolMajorVersion (2 bytes) */
Stream_Read_UINT16(s, VersionMinor); /* protocolMinorVersion (2 bytes) */
Stream_Read_UINT32(s, ioCode1); /* ioCode1 (4 bytes) */
Stream_Seek_UINT32(s); /* ioCode2 (4 bytes), must be set to zero, reserved for future use */
Stream_Read_UINT32(s, extendedPdu); /* extendedPdu (4 bytes) */
Stream_Read_UINT32(s, extraFlags1); /* extraFlags1 (4 bytes) */
Stream_Seek_UINT32(s); /* extraFlags2 (4 bytes), must be set to zero, reserved for future use */
Stream_Read_UINT32(s, SpecialTypeDeviceCap); /* SpecialTypeDeviceCap (4 bytes) */
context->priv->UserLoggedOnPdu = (extendedPdu & RDPDR_USER_LOGGEDON_PDU) ? TRUE : FALSE;
return 0;
}
static int rdpdr_server_write_general_capability_set(RdpdrServerContext* context, wStream* s)
{
UINT32 ioCode1;
UINT32 extendedPdu;
UINT32 extraFlags1;
UINT32 SpecialTypeDeviceCap;
RDPDR_CAPABILITY_HEADER header;
header.CapabilityType = CAP_GENERAL_TYPE;
header.CapabilityLength = RDPDR_CAPABILITY_HEADER_LENGTH + 36;
header.Version = GENERAL_CAPABILITY_VERSION_02;
ioCode1 = 0;
ioCode1 |= RDPDR_IRP_MJ_CREATE; /* always set */
ioCode1 |= RDPDR_IRP_MJ_CLEANUP; /* always set */
ioCode1 |= RDPDR_IRP_MJ_CLOSE; /* always set */
ioCode1 |= RDPDR_IRP_MJ_READ; /* always set */
ioCode1 |= RDPDR_IRP_MJ_WRITE; /* always set */
ioCode1 |= RDPDR_IRP_MJ_FLUSH_BUFFERS; /* always set */
ioCode1 |= RDPDR_IRP_MJ_SHUTDOWN; /* always set */
ioCode1 |= RDPDR_IRP_MJ_DEVICE_CONTROL; /* always set */
ioCode1 |= RDPDR_IRP_MJ_QUERY_VOLUME_INFORMATION; /* always set */
ioCode1 |= RDPDR_IRP_MJ_SET_VOLUME_INFORMATION; /* always set */
ioCode1 |= RDPDR_IRP_MJ_QUERY_INFORMATION; /* always set */
ioCode1 |= RDPDR_IRP_MJ_SET_INFORMATION; /* always set */
ioCode1 |= RDPDR_IRP_MJ_DIRECTORY_CONTROL; /* always set */
ioCode1 |= RDPDR_IRP_MJ_LOCK_CONTROL; /* always set */
ioCode1 |= RDPDR_IRP_MJ_QUERY_SECURITY; /* optional */
ioCode1 |= RDPDR_IRP_MJ_SET_SECURITY; /* optional */
extendedPdu = 0;
extendedPdu |= RDPDR_CLIENT_DISPLAY_NAME_PDU; /* always set */
extendedPdu |= RDPDR_DEVICE_REMOVE_PDUS; /* optional */
if (context->priv->UserLoggedOnPdu)
extendedPdu |= RDPDR_USER_LOGGEDON_PDU; /* optional */
extraFlags1 = 0;
extraFlags1 |= ENABLE_ASYNCIO; /* optional */
SpecialTypeDeviceCap = 0;
Stream_EnsureRemainingCapacity(s, header.CapabilityLength);
rdpdr_server_write_capability_set_header(s, &header);
Stream_Write_UINT32(s, 0); /* osType (4 bytes), ignored on receipt */
Stream_Write_UINT32(s, 0); /* osVersion (4 bytes), unused and must be set to zero */
Stream_Write_UINT16(s, context->priv->VersionMajor); /* protocolMajorVersion (2 bytes) */
Stream_Write_UINT16(s, context->priv->VersionMinor); /* protocolMinorVersion (2 bytes) */
Stream_Write_UINT32(s, ioCode1); /* ioCode1 (4 bytes) */
Stream_Write_UINT32(s, 0); /* ioCode2 (4 bytes), must be set to zero, reserved for future use */
Stream_Write_UINT32(s, extendedPdu); /* extendedPdu (4 bytes) */
Stream_Write_UINT32(s, extraFlags1); /* extraFlags1 (4 bytes) */
Stream_Write_UINT32(s, 0); /* extraFlags2 (4 bytes), must be set to zero, reserved for future use */
Stream_Write_UINT32(s, SpecialTypeDeviceCap); /* SpecialTypeDeviceCap (4 bytes) */
return 0;
}
static int rdpdr_server_read_printer_capability_set(RdpdrServerContext* context, wStream* s, RDPDR_CAPABILITY_HEADER* header)
{
return 0;
}
static int rdpdr_server_write_printer_capability_set(RdpdrServerContext* context, wStream* s)
{
RDPDR_CAPABILITY_HEADER header;
header.CapabilityType = CAP_PRINTER_TYPE;
header.CapabilityLength = RDPDR_CAPABILITY_HEADER_LENGTH;
header.Version = PRINT_CAPABILITY_VERSION_01;
Stream_EnsureRemainingCapacity(s, header.CapabilityLength);
rdpdr_server_write_capability_set_header(s, &header);
return 0;
}
static int rdpdr_server_read_port_capability_set(RdpdrServerContext* context, wStream* s, RDPDR_CAPABILITY_HEADER* header)
{
return 0;
}
static int rdpdr_server_write_port_capability_set(RdpdrServerContext* context, wStream* s)
{
RDPDR_CAPABILITY_HEADER header;
header.CapabilityType = CAP_PORT_TYPE;
header.CapabilityLength = RDPDR_CAPABILITY_HEADER_LENGTH;
header.Version = PORT_CAPABILITY_VERSION_01;
Stream_EnsureRemainingCapacity(s, header.CapabilityLength);
rdpdr_server_write_capability_set_header(s, &header);
return 0;
}
static int rdpdr_server_read_drive_capability_set(RdpdrServerContext* context, wStream* s, RDPDR_CAPABILITY_HEADER* header)
{
return 0;
}
static int rdpdr_server_write_drive_capability_set(RdpdrServerContext* context, wStream* s)
{
RDPDR_CAPABILITY_HEADER header;
header.CapabilityType = CAP_DRIVE_TYPE;
header.CapabilityLength = RDPDR_CAPABILITY_HEADER_LENGTH;
header.Version = DRIVE_CAPABILITY_VERSION_02;
Stream_EnsureRemainingCapacity(s, header.CapabilityLength);
rdpdr_server_write_capability_set_header(s, &header);
return 0;
}
static int rdpdr_server_read_smartcard_capability_set(RdpdrServerContext* context, wStream* s, RDPDR_CAPABILITY_HEADER* header)
{
return 0;
}
static int rdpdr_server_write_smartcard_capability_set(RdpdrServerContext* context, wStream* s)
{
RDPDR_CAPABILITY_HEADER header;
header.CapabilityType = CAP_SMARTCARD_TYPE;
header.CapabilityLength = RDPDR_CAPABILITY_HEADER_LENGTH;
header.Version = SMARTCARD_CAPABILITY_VERSION_01;
Stream_EnsureRemainingCapacity(s, header.CapabilityLength);
rdpdr_server_write_capability_set_header(s, &header);
return 0;
}
static int rdpdr_server_send_core_capability_request(RdpdrServerContext* context)
{
wStream* s;
BOOL status;
RDPDR_HEADER header;
UINT16 numCapabilities;
ULONG written;
printf("RdpdrServerSendCoreCapabilityRequest\n");
header.Component = RDPDR_CTYP_CORE;
header.PacketId = PAKID_CORE_SERVER_CAPABILITY;
numCapabilities = 5;
s = Stream_New(NULL, RDPDR_HEADER_LENGTH + 512);
Stream_Write_UINT16(s, header.Component); /* Component (2 bytes) */
Stream_Write_UINT16(s, header.PacketId); /* PacketId (2 bytes) */
Stream_Write_UINT16(s, numCapabilities); /* numCapabilities (2 bytes) */
Stream_Write_UINT16(s, 0); /* Padding (2 bytes) */
rdpdr_server_write_general_capability_set(context, s);
rdpdr_server_write_printer_capability_set(context, s);
rdpdr_server_write_port_capability_set(context, s);
rdpdr_server_write_drive_capability_set(context, s);
rdpdr_server_write_smartcard_capability_set(context, s);
Stream_SealLength(s);
status = WTSVirtualChannelWrite(context->priv->ChannelHandle, (PCHAR) Stream_Buffer(s), Stream_Length(s), &written);
Stream_Free(s, TRUE);
return 0;
}
static int rdpdr_server_receive_core_capability_response(RdpdrServerContext* context, wStream* s, RDPDR_HEADER* header)
{
int i;
UINT16 numCapabilities;
RDPDR_CAPABILITY_HEADER capabilityHeader;
Stream_Read_UINT16(s, numCapabilities); /* numCapabilities (2 bytes) */
Stream_Seek_UINT16(s); /* Padding (2 bytes) */
for (i = 0; i < numCapabilities; i++)
{
rdpdr_server_read_capability_set_header(s, &capabilityHeader);
switch (capabilityHeader.CapabilityType)
{
case CAP_GENERAL_TYPE:
rdpdr_server_read_general_capability_set(context, s, &capabilityHeader);
break;
case CAP_PRINTER_TYPE:
rdpdr_server_read_printer_capability_set(context, s, &capabilityHeader);
break;
case CAP_PORT_TYPE:
rdpdr_server_read_port_capability_set(context, s, &capabilityHeader);
break;
case CAP_DRIVE_TYPE:
rdpdr_server_read_drive_capability_set(context, s, &capabilityHeader);
break;
case CAP_SMARTCARD_TYPE:
rdpdr_server_read_smartcard_capability_set(context, s, &capabilityHeader);
break;
default:
printf("Unknown capabilityType %d\n", capabilityHeader.CapabilityType);
Stream_Seek(s, capabilityHeader.CapabilityLength - RDPDR_CAPABILITY_HEADER_LENGTH);
break;
}
}
return 0;
}
static int rdpdr_server_send_client_id_confirm(RdpdrServerContext* context)
{
wStream* s;
BOOL status;
RDPDR_HEADER header;
ULONG written;
printf("RdpdrServerSendClientIdConfirm\n");
header.Component = RDPDR_CTYP_CORE;
header.PacketId = PAKID_CORE_CLIENTID_CONFIRM;
s = Stream_New(NULL, RDPDR_HEADER_LENGTH + 8);
Stream_Write_UINT16(s, header.Component); /* Component (2 bytes) */
Stream_Write_UINT16(s, header.PacketId); /* PacketId (2 bytes) */
Stream_Write_UINT16(s, context->priv->VersionMajor); /* VersionMajor (2 bytes) */
Stream_Write_UINT16(s, context->priv->VersionMinor); /* VersionMinor (2 bytes) */
Stream_Write_UINT32(s, context->priv->ClientId); /* ClientId (4 bytes) */
Stream_SealLength(s);
status = WTSVirtualChannelWrite(context->priv->ChannelHandle, (PCHAR) Stream_Buffer(s), Stream_Length(s), &written);
Stream_Free(s, TRUE);
return 0;
}
static int rdpdr_server_receive_device_list_announce_request(RdpdrServerContext* context, wStream* s, RDPDR_HEADER* header)
{
int i;
UINT32 DeviceCount;
UINT32 DeviceType;
UINT32 DeviceId;
char PreferredDosName[9];
UINT32 DeviceDataLength;
PreferredDosName[8] = 0;
Stream_Read_UINT32(s, DeviceCount); /* DeviceCount (4 bytes) */
printf("%s: DeviceCount: %d\n", __FUNCTION__, DeviceCount);
for (i = 0; i < DeviceCount; i++)
{
Stream_Read_UINT32(s, DeviceType); /* DeviceType (4 bytes) */
Stream_Read_UINT32(s, DeviceId); /* DeviceId (4 bytes) */
Stream_Read(s, PreferredDosName, 8); /* PreferredDosName (8 bytes) */
Stream_Read_UINT32(s, DeviceDataLength); /* DeviceDataLength (4 bytes) */
printf("Device %d Name: %s Id: 0x%04X DataLength: %d\n",
i, PreferredDosName, DeviceId, DeviceDataLength);
switch (DeviceId)
{
case RDPDR_DTYP_FILESYSTEM:
break;
case RDPDR_DTYP_PRINT:
break;
case RDPDR_DTYP_SERIAL:
break;
case RDPDR_DTYP_PARALLEL:
break;
case RDPDR_DTYP_SMARTCARD:
break;
default:
break;
}
Stream_Seek(s, DeviceDataLength);
}
return 0;
}
static int rdpdr_server_send_user_logged_on(RdpdrServerContext* context)
{
wStream* s;
BOOL status;
RDPDR_HEADER header;
ULONG written;
printf("%s\n", __FUNCTION__);
header.Component = RDPDR_CTYP_CORE;
header.PacketId = PAKID_CORE_USER_LOGGEDON;
s = Stream_New(NULL, RDPDR_HEADER_LENGTH);
Stream_Write_UINT16(s, header.Component); /* Component (2 bytes) */
Stream_Write_UINT16(s, header.PacketId); /* PacketId (2 bytes) */
Stream_SealLength(s);
status = WTSVirtualChannelWrite(context->priv->ChannelHandle, (PCHAR) Stream_Buffer(s), Stream_Length(s), &written);
Stream_Free(s, TRUE);
return 0;
}
static int rdpdr_server_receive_pdu(RdpdrServerContext* context, wStream* s, RDPDR_HEADER* header)
{
printf("RdpdrServerReceivePdu: Component: 0x%04X PacketId: 0x%04X\n",
header->Component, header->PacketId);
winpr_HexDump(Stream_Buffer(s), Stream_Length(s));
if (header->Component == RDPDR_CTYP_CORE)
{
switch (header->PacketId)
{
case PAKID_CORE_CLIENTID_CONFIRM:
rdpdr_server_receive_announce_response(context, s, header);
break;
case PAKID_CORE_CLIENT_NAME:
rdpdr_server_receive_client_name_request(context, s, header);
rdpdr_server_send_core_capability_request(context);
break;
case PAKID_CORE_CLIENT_CAPABILITY:
rdpdr_server_receive_core_capability_response(context, s, header);
rdpdr_server_send_client_id_confirm(context);
if (context->priv->UserLoggedOnPdu)
rdpdr_server_send_user_logged_on(context);
break;
case PAKID_CORE_DEVICELIST_ANNOUNCE:
rdpdr_server_receive_device_list_announce_request(context, s, header);
break;
case PAKID_CORE_DEVICE_REPLY:
break;
case PAKID_CORE_DEVICE_IOREQUEST:
break;
case PAKID_CORE_DEVICE_IOCOMPLETION:
break;
case PAKID_CORE_DEVICELIST_REMOVE:
break;
default:
break;
}
}
else if (header->Component == RDPDR_CTYP_PRN)
{
switch (header->PacketId)
{
case PAKID_PRN_CACHE_DATA:
break;
case PAKID_PRN_USING_XPS:
break;
default:
break;
}
}
else
{
printf("Unknown RDPDR_HEADER.Component: 0x%04X\n", header->Component);
return -1;
}
return 0;
}
static void* rdpdr_server_thread(void* arg)
{
wStream* s;
DWORD status;
DWORD nCount;
void* buffer;
int position;
HANDLE events[8];
RDPDR_HEADER header;
HANDLE ChannelEvent;
DWORD BytesReturned;
RdpdrServerContext* context;
context = (RdpdrServerContext*) arg;
buffer = NULL;
BytesReturned = 0;
ChannelEvent = NULL;
s = Stream_New(NULL, 4096);
if (WTSVirtualChannelQuery(context->priv->ChannelHandle, WTSVirtualEventHandle, &buffer, &BytesReturned) == TRUE)
{
if (BytesReturned == sizeof(HANDLE))
CopyMemory(&ChannelEvent, buffer, sizeof(HANDLE));
WTSFreeMemory(buffer);
}
nCount = 0;
events[nCount++] = ChannelEvent;
events[nCount++] = context->priv->StopEvent;
rdpdr_server_send_announce_request(context);
while (1)
{
BytesReturned = 0;
status = WaitForMultipleObjects(nCount, events, FALSE, INFINITE);
if (WaitForSingleObject(context->priv->StopEvent, 0) == WAIT_OBJECT_0)
{
break;
}
if (WTSVirtualChannelRead(context->priv->ChannelHandle, 0, (PCHAR) Stream_Pointer(s),
Stream_Capacity(s) - Stream_GetPosition(s), &BytesReturned))
{
if (BytesReturned)
Stream_Seek(s, BytesReturned);
}
else
{
Stream_EnsureRemainingCapacity(s, BytesReturned);
}
if (Stream_GetPosition(s) >= RDPDR_HEADER_LENGTH)
{
position = Stream_GetPosition(s);
Stream_SetPosition(s, 0);
Stream_Read_UINT16(s, header.Component); /* Component (2 bytes) */
Stream_Read_UINT16(s, header.PacketId); /* PacketId (2 bytes) */
Stream_SetPosition(s, position);
Stream_SealLength(s);
Stream_SetPosition(s, RDPDR_HEADER_LENGTH);
rdpdr_server_receive_pdu(context, s, &header);
Stream_SetPosition(s, 0);
}
}
Stream_Free(s, TRUE);
return NULL;
}
static int rdpdr_server_start(RdpdrServerContext* context)
{
context->priv->ChannelHandle = WTSVirtualChannelOpen(context->vcm, WTS_CURRENT_SESSION, "rdpdr");
if (!context->priv->ChannelHandle)
return -1;
context->priv->StopEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
context->priv->Thread = CreateThread(NULL, 0,
(LPTHREAD_START_ROUTINE) rdpdr_server_thread, (void*) context, 0, NULL);
return 0;
}
static int rdpdr_server_stop(RdpdrServerContext* context)
{
SetEvent(context->priv->StopEvent);
WaitForSingleObject(context->priv->Thread, INFINITE);
CloseHandle(context->priv->Thread);
return 0;
}
RdpdrServerContext* rdpdr_server_context_new(HANDLE vcm)
{
RdpdrServerContext* context;
context = (RdpdrServerContext*) malloc(sizeof(RdpdrServerContext));
if (context)
{
ZeroMemory(context, sizeof(RdpdrServerContext));
context->vcm = vcm;
context->Start = rdpdr_server_start;
context->Stop = rdpdr_server_stop;
context->priv = (RdpdrServerPrivate*) malloc(sizeof(RdpdrServerPrivate));
if (context->priv)
{
ZeroMemory(context->priv, sizeof(RdpdrServerPrivate));
context->priv->VersionMajor = RDPDR_VERSION_MAJOR;
context->priv->VersionMinor = RDPDR_VERSION_MINOR_RDP6X;
context->priv->ClientId = g_ClientId++;
context->priv->UserLoggedOnPdu = TRUE;
}
}
return context;
}
void rdpdr_server_context_free(RdpdrServerContext* context)
{
if (context)
{
if (context->priv)
{
free(context->priv);
}
free(context);
}
}