MdeModulePkg/Universal/Network/Tcp4Dxe/Tcp4Option.h

   1 /** @file
   2   Tcp option's routine header file.
   3
   4 Copyright (c) 2005 - 2018, Intel Corporation. All rights reserved.<BR>
   5 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 //
  31 // supported TCP option type and their length
  32 //
  33 #define TCP_OPTION_EOP             0  ///< End Of oPtion
  34 #define TCP_OPTION_NOP             1  ///< No-Option.
  35 #define TCP_OPTION_MSS             2  ///< Maximum Segment Size
  36 #define TCP_OPTION_WS              3  ///< Window scale
  37 #define TCP_OPTION_TS              8  ///< Timestamp
  38 #define TCP_OPTION_MSS_LEN         4  ///< Length of MSS option
  39 #define TCP_OPTION_WS_LEN          3  ///< Length of window scale option
  40 #define TCP_OPTION_TS_LEN          10 ///< Length of timestamp option
  41 #define TCP_OPTION_WS_ALIGNED_LEN  4  ///< Length of window scale option, aligned
  42 #define TCP_OPTION_TS_ALIGNED_LEN  12 ///< Length of timestamp option, aligned
  43
  44 //
  45 // recommend format of timestamp window scale
  46 // option for fast process.
  47 //
  48 #define TCP_OPTION_TS_FAST ((TCP_OPTION_NOP << 24) | \
  49                             (TCP_OPTION_NOP << 16) | \
  50                             (TCP_OPTION_TS << 8)   | \
  51                             (TCP_OPTION_TS_LEN))
  52
  53 #define TCP_OPTION_WS_FAST   ((TCP_OPTION_NOP << 24) | \
  54                               (TCP_OPTION_WS << 16)  | \
  55                               (TCP_OPTION_WS_LEN << 8))
  56
  57 #define TCP_OPTION_MSS_FAST  ((TCP_OPTION_MSS << 24) | (TCP_OPTION_MSS_LEN << 16))
  58
  59 //
  60 // Other misc definations
  61 //
  62 #define TCP_OPTION_RCVD_MSS        0x01
  63 #define TCP_OPTION_RCVD_WS         0x02
  64 #define TCP_OPTION_RCVD_TS         0x04
  65 #define TCP_OPTION_MAX_WS          14      ///< Maxium window scale value
  66 #define TCP_OPTION_MAX_WIN         0xffff  ///< Max window size in TCP header
  67
  68
  69 /**
  70   Compute the window scale value according to the given buffer size.
  71
  72   @param  Tcb     Pointer to the TCP_CB of this TCP instance.
  73
  74   @return  The scale value.
  75
  76 **/
  77 UINT8
  78 TcpComputeScale (
  79   IN TCP_CB *Tcb
  80   );
  81
  82 /**
  83   Build the TCP option in three-way handshake.
  84
  85   @param  Tcb     Pointer to the TCP_CB of this TCP instance.
  86   @param  Nbuf    Pointer to the buffer to store the options.
  87
  88   @return  The total length of the TCP option field.
  89
  90 **/
  91 UINT16
  92 TcpSynBuildOption (
  93   IN TCP_CB  *Tcb,
  94   IN NET_BUF *Nbuf
  95   );
  96
  97 /**
  98   Build the TCP option in synchronized states.
  99
 100   @param  Tcb     Pointer to the TCP_CB of this TCP instance.
 101   @param  Nbuf    Pointer to the buffer to store the options.
 102
 103   @return  The total length of the TCP option field.
 104
 105 **/
 106 UINT16
 107 TcpBuildOption (
 108   IN TCP_CB  *Tcb,
 109   IN NET_BUF *Nbuf
 110   );
 111
 112 /**
 113   Parse the supported options.
 114
 115   @param  Tcp     Pointer to the TCP_CB of this TCP instance.
 116   @param  Option  Pointer to the TCP_OPTION used to store the successfully pasrsed
 117                   options.
 118
 119   @retval 0       The options are successfully pasrsed.
 120   @retval -1      Ilegal option was found.
 121
 122 **/
 123 INTN
 124 TcpParseOption (
 125   IN     TCP_HEAD   *Tcp,
 126   IN OUT TCP_OPTION *Option
 127   );
 128
 129 /**
 130   Check the segment against PAWS.
 131
 132   @param  Tcb     Pointer to the TCP_CB of this TCP instance.
 133   @param  TSVal   The timestamp value.
 134
 135   @retval 1       The segment passed the PAWS check.
 136   @retval 0       The segment failed to pass the PAWS check.
 137
 138 **/
 139 UINT32
 140 TcpPawsOK (
 141   IN TCP_CB *Tcb,
 142   IN UINT32 TSVal
 143   );
 144
 145 #endif