NetworkPkg/TcpDxe/TcpOption.h

   1 /** @file
   2   Tcp option's routine header file.
   3
   4   Copyright (c) 2009 - 2018, Intel Corporation. All rights reserved.<BR>
   5
   6   SPDX-License-Identifier: BSD-2-Clause-Patent
   7
   8 **/
   9
  10 #ifndef _TCP_OPTION_H_
  11 #define _TCP_OPTION_H_
  12
  13 //
  14 // Supported TCP option types and their length.
  15 //
  16 #define TCP_OPTION_EOP             0  ///< End Of oPtion
  17 #define TCP_OPTION_NOP             1  ///< No-Option.
  18 #define TCP_OPTION_MSS             2  ///< Maximum Segment Size
  19 #define TCP_OPTION_WS              3  ///< Window scale
  20 #define TCP_OPTION_TS              8  ///< Timestamp
  21 #define TCP_OPTION_MSS_LEN         4  ///< Length of MSS option
  22 #define TCP_OPTION_WS_LEN          3  ///< Length of window scale option
  23 #define TCP_OPTION_TS_LEN          10 ///< Length of timestamp option
  24 #define TCP_OPTION_WS_ALIGNED_LEN  4  ///< Length of window scale option, aligned
  25 #define TCP_OPTION_TS_ALIGNED_LEN  12 ///< Length of timestamp option, aligned
  26
  27 //
  28 // recommend format of timestamp window scale
  29 // option for fast process.
  30 //
  31 #define TCP_OPTION_TS_FAST ((TCP_OPTION_NOP << 24) | \
  32                             (TCP_OPTION_NOP << 16) | \
  33                             (TCP_OPTION_TS << 8)   | \
  34                             (TCP_OPTION_TS_LEN))
  35
  36 #define TCP_OPTION_WS_FAST   ((TCP_OPTION_NOP << 24) | \
  37                               (TCP_OPTION_WS << 16)  | \
  38                               (TCP_OPTION_WS_LEN << 8))
  39
  40 #define TCP_OPTION_MSS_FAST  ((TCP_OPTION_MSS << 24) | (TCP_OPTION_MSS_LEN << 16))
  41
  42 //
  43 // Other misc definations
  44 //
  45 #define TCP_OPTION_RCVD_MSS        0x01
  46 #define TCP_OPTION_RCVD_WS         0x02
  47 #define TCP_OPTION_RCVD_TS         0x04
  48 #define TCP_OPTION_MAX_WS          14      ///< Maxium window scale value
  49 #define TCP_OPTION_MAX_WIN         0xffff  ///< Max window size in TCP header
  50
  51 ///
  52 /// The structure to store the parse option value.
  53 /// ParseOption only parses the options, doesn't process them.
  54 ///
  55 typedef struct _TCP_OPTION {
  56   UINT8   Flag;     ///< Flag such as TCP_OPTION_RCVD_MSS
  57   UINT8   WndScale; ///< The WndScale received
  58   UINT16  Mss;      ///< The Mss received
  59   UINT32  TSVal;    ///< The TSVal field in a timestamp option
  60   UINT32  TSEcr;    ///< The TSEcr field in a timestamp option
  61 } TCP_OPTION;
  62
  63 /**
  64   Compute the window scale value according to the given buffer size.
  65
  66   @param[in]  Tcb Pointer to the TCP_CB of this TCP instance.
  67
  68   @return         The scale value.
  69
  70 **/
  71 UINT8
  72 TcpComputeScale (
  73   IN TCP_CB *Tcb
  74   );
  75
  76 /**
  77   Build the TCP option in three-way handshake.
  78
  79   @param[in]  Tcb     Pointer to the TCP_CB of this TCP instance.
  80   @param[in]  Nbuf    Pointer to the buffer to store the options.
  81
  82   @return             The total length of the TCP option field.
  83
  84 **/
  85 UINT16
  86 TcpSynBuildOption (
  87   IN TCP_CB  *Tcb,
  88   IN NET_BUF *Nbuf
  89   );
  90
  91 /**
  92   Build the TCP option in synchronized states.
  93
  94   @param[in]  Tcb     Pointer to the TCP_CB of this TCP instance.
  95   @param[in]  Nbuf    Pointer to the buffer to store the options.
  96
  97   @return             The total length of the TCP option field.
  98
  99 **/
 100 UINT16
 101 TcpBuildOption (
 102   IN TCP_CB  *Tcb,
 103   IN NET_BUF *Nbuf
 104   );
 105
 106 /**
 107   Parse the supported options.
 108
 109   @param[in]       Tcp     Pointer to the TCP_CB of this TCP instance.
 110   @param[in, out]  Option  Pointer to the TCP_OPTION used to store the
 111                            successfully pasrsed options.
 112
 113   @retval          0       The options successfully pasrsed.
 114   @retval          -1      Ilegal option was found.
 115
 116 **/
 117 INTN
 118 TcpParseOption (
 119   IN     TCP_HEAD   *Tcp,
 120   IN OUT TCP_OPTION *Option
 121   );
 122
 123 #endif