73cdcdfe09
* Fixed remdesk settings pointer * Fixed sign warnings in display_write_monitor_layout_pdu * Use freerdp_abort_connect_context and freerdp_shall_disconnect_context * Added and updates settings * info assert/dynamic timezone * mcs assert/log/flags * Fixed and added assertions for wStream * Unified stream length checks * Added new function to check for lenght and log * Replace all usages with this new function * Cleaned up PER, added parser logging * Cleaned up BER, added parser logging * log messages * Modified Stream_CheckAndLogRequiredLengthEx * Allow custom format and options * Add Stream_CheckAndLogRequiredLengthExVa for prepared va_list * Improved Stream_CheckAndLogRequiredLength * Now have log level adjustable * Added function equivalents for existing logger * Added a backtrace in case of a failure is detected * Fixed public API input checks
158 lines
3.6 KiB
C
158 lines
3.6 KiB
C
/**
|
|
* FreeRDP: A Remote Desktop Protocol Implementation
|
|
* Transport Packets (TPKTs)
|
|
*
|
|
* Copyright 2011 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.
|
|
*/
|
|
|
|
#include <freerdp/config.h>
|
|
|
|
#include "tpdu.h"
|
|
|
|
#include "tpkt.h"
|
|
|
|
#include <winpr/wlog.h>
|
|
|
|
#define TAG FREERDP_TAG("core.tpkt")
|
|
|
|
/**
|
|
* TPKTs are defined in:
|
|
*
|
|
* http://tools.ietf.org/html/rfc1006/
|
|
* RFC 1006 - ISO Transport Service on top of the TCP
|
|
*
|
|
* http://www.itu.int/rec/T-REC-T.123/
|
|
* ITU-T T.123 (01/2007) - Network-specific data protocol stacks for multimedia conferencing
|
|
*
|
|
* TPKT Header
|
|
* ____________________ byte
|
|
* | |
|
|
* | 3 (version) | 1
|
|
* |____________________|
|
|
* | |
|
|
* | Reserved | 2
|
|
* |____________________|
|
|
* | |
|
|
* | Length (MSB) | 3
|
|
* |____________________|
|
|
* | |
|
|
* | Length (LSB) | 4
|
|
* |____________________|
|
|
* | |
|
|
* | X.224 TPDU | 5 - ?
|
|
* ....
|
|
*
|
|
* A TPKT header is of fixed length 4, and the following X.224 TPDU is at least three bytes long.
|
|
* Therefore, the minimum TPKT length is 7, and the maximum TPKT length is 65535. Because the TPKT
|
|
* length includes the TPKT header (4 bytes), the maximum X.224 TPDU length is 65531.
|
|
*/
|
|
|
|
/**
|
|
* Verify if a packet has valid TPKT header.\n
|
|
* @param s
|
|
* @return BOOL
|
|
*/
|
|
|
|
BOOL tpkt_verify_header(wStream* s)
|
|
{
|
|
BYTE version;
|
|
|
|
WINPR_ASSERT(s);
|
|
|
|
Stream_Peek_UINT8(s, version);
|
|
|
|
if (version == 3)
|
|
return TRUE;
|
|
else
|
|
return FALSE;
|
|
}
|
|
|
|
/**
|
|
* Read a TPKT header.\n
|
|
* @param s
|
|
* @param length
|
|
* @return success
|
|
*/
|
|
|
|
BOOL tpkt_read_header(wStream* s, UINT16* length)
|
|
{
|
|
BYTE version;
|
|
|
|
if (!Stream_CheckAndLogRequiredLength(TAG, s, 1))
|
|
return FALSE;
|
|
|
|
Stream_Peek_UINT8(s, version);
|
|
|
|
if (version == 3)
|
|
{
|
|
UINT16 len;
|
|
if (!Stream_CheckAndLogRequiredLength(TAG, s, 4))
|
|
return FALSE;
|
|
|
|
Stream_Seek(s, 2);
|
|
Stream_Read_UINT16_BE(s, len);
|
|
|
|
/* ITU-T Rec. T.123 8 Packet header to delimit data units in an octet stream */
|
|
if (len < 7)
|
|
{
|
|
WLog_ERR(TAG, "TPKT header too short, require minimum of 7 bytes, got %" PRId16, len);
|
|
return FALSE;
|
|
}
|
|
|
|
if (!Stream_CheckAndLogRequiredLength(TAG, s, len - 4))
|
|
{
|
|
WLog_ERR(TAG, "TPKT header length %" PRIu16 ", but received less", len);
|
|
return FALSE;
|
|
}
|
|
*length = len;
|
|
}
|
|
else
|
|
{
|
|
/* not a TPKT header */
|
|
*length = 0;
|
|
}
|
|
|
|
return TRUE;
|
|
}
|
|
|
|
BOOL tpkt_ensure_stream_consumed_(wStream* s, UINT16 length, const char* fkt)
|
|
{
|
|
size_t rem = Stream_GetRemainingLength(s);
|
|
if (rem > 0)
|
|
{
|
|
WLog_ERR(TAG,
|
|
"[%s] Received invalid TPKT header length %" PRIu16 ", %" PRIdz " bytes too long!",
|
|
fkt, length, rem);
|
|
return FALSE;
|
|
}
|
|
return TRUE;
|
|
}
|
|
|
|
/**
|
|
* Write a TPKT header.\n
|
|
* @param s
|
|
* @param length
|
|
*/
|
|
|
|
BOOL tpkt_write_header(wStream* s, UINT16 length)
|
|
{
|
|
if (Stream_GetRemainingCapacity(s) < 4)
|
|
return FALSE;
|
|
Stream_Write_UINT8(s, 3); /* version */
|
|
Stream_Write_UINT8(s, 0); /* reserved */
|
|
Stream_Write_UINT16_BE(s, length); /* length */
|
|
return TRUE;
|
|
}
|