MdeModulePkg/Universal/Network/Tcp4Dxe/Tcp4Option.h

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