MdeModulePkg/Universal/Network/Tcp4Dxe/Tcp4Option.h

   1 /** @file
   2
   3 Copyright (c) 2005 - 2006, Intel Corporation<BR>
   4 All rights reserved. This program and the accompanying materials
   5 are licensed and made available under the terms and conditions of the BSD License
   6 which accompanies this distribution.  The full text of the license may be found at
   7 http://opensource.org/licenses/bsd-license.php<BR>
   8
   9 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11
  12 **/
  13
  14 #ifndef _TCP4_OPTION_H_
  15 #define _TCP4_OPTION_H_
  16
  17 ///
  18 /// The structure to store the parse option value.
  19 /// ParseOption only parse the options, don't process them.
  20 ///
  21 typedef struct _TCP_OPTION {
  22   UINT8   Flag;     ///< Flag such as TCP_OPTION_RCVD_MSS
  23   UINT8   WndScale; ///< The WndScale received
  24   UINT16  Mss;      ///< The Mss received
  25   UINT32  TSVal;    ///< The TSVal field in a timestamp option
  26   UINT32  TSEcr;    ///< The TSEcr field in a timestamp option
  27 } TCP_OPTION;
  28
  29 typedef enum {
  30
  31   //
  32   // supported TCP option type and their length
  33   //
  34   TCP_OPTION_EOP            = 0,  ///< End Of oPtion
  35   TCP_OPTION_NOP            = 1,  ///< No-Option.
  36   TCP_OPTION_MSS            = 2,  ///< Maximum Segment Size
  37   TCP_OPTION_WS             = 3,  ///< Window scale
  38   TCP_OPTION_TS             = 8,  ///< Timestamp
  39   TCP_OPTION_MSS_LEN        = 4,  ///< Length of MSS option
  40   TCP_OPTION_WS_LEN         = 3,  ///< Length of window scale option
  41   TCP_OPTION_TS_LEN         = 10, ///< Length of timestamp option
  42   TCP_OPTION_WS_ALIGNED_LEN = 4,  ///< Length of window scale option, aligned
  43   TCP_OPTION_TS_ALIGNED_LEN = 12, ///< Length of timestamp option, aligned
  44
  45   //
  46   // recommend format of timestamp window scale
  47   // option for fast process.
  48   //
  49   TCP_OPTION_TS_FAST = ((TCP_OPTION_NOP << 24) |
  50                         (TCP_OPTION_NOP << 16) |
  51                         (TCP_OPTION_TS << 8) |
  52                         TCP_OPTION_TS_LEN),
  53
  54   TCP_OPTION_WS_FAST = ((TCP_OPTION_NOP << 24) |
  55                         (TCP_OPTION_WS << 16) |
  56                         (TCP_OPTION_WS_LEN << 8)),
  57
  58   TCP_OPTION_MSS_FAST = ((TCP_OPTION_MSS << 24) |
  59                          (TCP_OPTION_MSS_LEN << 16)),
  60
  61   //
  62   // Other misc definations
  63   //
  64   TCP_OPTION_RCVD_MSS       = 0x01,
  65   TCP_OPTION_RCVD_WS        = 0x02,
  66   TCP_OPTION_RCVD_TS        = 0x04,
  67   TCP_OPTION_MAX_WS         = 14,     ///< Maxium window scale value
  68   TCP_OPTION_MAX_WIN        = 0xffff  ///< Max window size in TCP header
  69 } TCP_OPTION_TYPE;
  70
  71 /**
  72   Compute the window scale value according to the given buffer size.
  73
  74   @param  Tcb     Pointer to the TCP_CB of this TCP instance.
  75
  76   @return  The scale value.
  77
  78 **/
  79 UINT8
  80 TcpComputeScale (
  81   IN TCP_CB *Tcb
  82   );
  83
  84 /**
  85   Build the TCP option in three-way handshake.
  86
  87   @param  Tcb     Pointer to the TCP_CB of this TCP instance.
  88   @param  Nbuf    Pointer to the buffer to store the options.
  89
  90   @return  The total length of the TCP option field.
  91
  92 **/
  93 UINT16
  94 TcpSynBuildOption (
  95   IN TCP_CB  *Tcb,
  96   IN NET_BUF *Nbuf
  97   );
  98
  99 /**
 100   Build the TCP option in synchronized states.
 101
 102   @param  Tcb     Pointer to the TCP_CB of this TCP instance.
 103   @param  Nbuf    Pointer to the buffer to store the options.
 104
 105   @return  The total length of the TCP option field.
 106
 107 **/
 108 UINT16
 109 TcpBuildOption (
 110   IN TCP_CB  *Tcb,
 111   IN NET_BUF *Nbuf
 112   );
 113
 114 /**
 115   Parse the supported options.
 116
 117   @param  Tcp     Pointer to the TCP_CB of this TCP instance.
 118   @param  Option  Pointer to the TCP_OPTION used to store the successfully pasrsed
 119                   options.
 120
 121   @retval 0       The options are successfully pasrsed.
 122   @retval -1      Ilegal option was found.
 123
 124 **/
 125 INTN
 126 TcpParseOption (
 127   IN     TCP_HEAD   *Tcp,
 128   IN OUT TCP_OPTION *Option
 129   );
 130
 131 /**
 132   Check the segment against PAWS.
 133
 134   @param  Tcb     Pointer to the TCP_CB of this TCP instance.
 135   @param  TSVal   The timestamp value.
 136
 137   @retval 1       The segment passed the PAWS check.
 138   @retval 0       The segment failed to pass the PAWS check.
 139
 140 **/
 141 UINT32
 142 TcpPawsOK (
 143   IN TCP_CB *Tcb,
 144   IN UINT32 TSVal
 145   );
 146
 147 #endif