tpkt.c

 
#include <freerdp/config.h>
 
#include "tpdu.h"
 
#include "tpkt.h"
 
#include <winpr/wlog.h>
 
#define TAG FREERDP_TAG("core.tpkt")
 
int tpkt_verify_header(wStream* s)
{
  BYTE version = 0;
 
  if (!Stream_CheckAndLogRequiredLength(TAG, s, 1))
    return -1;
 
  Stream_Peek_UINT8(s, version);
 
  if (version == 3)
    return 1;
  else
    return 0;
}
 
BOOL tpkt_read_header(wStream* s, UINT16* length)
{
  BYTE version = 0;
 
  if (!Stream_CheckAndLogRequiredLength(TAG, s, 1))
    return FALSE;
 
  Stream_Peek_UINT8(s, version);
 
  if (version == 3)
  {
    UINT16 len = 0;
    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, size_t length, const char* fkt)
{
  if (length > UINT16_MAX)
  {
    WLog_ERR(TAG, "[%s] length %" PRIuz " > %" PRIu16, fkt, length, UINT16_MAX);
    return FALSE;
  }
 
  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;
}
 
BOOL tpkt_write_header(wStream* s, size_t length)
{
  if (!Stream_CheckAndLogRequiredCapacity(TAG, (s), 4))
    return FALSE;
  Stream_Write_UINT8(s, 3);          /* version */
  Stream_Write_UINT8(s, 0);          /* reserved */
 
  WINPR_ASSERT(length <= UINT16_MAX);
  Stream_Write_UINT16_BE(s, (UINT16)length); /* length */
  return TRUE;
}