NetworkPkg/TcpDxe/TcpOption.h

   1 /** @file
   2   Tcp option's routine header file.
   3
   4   Copyright (c) 2009 - 2010, Intel Corporation. All rights reserved.<BR>
   5
   6   This program and the accompanying materials
   7   are licensed and made available under the terms and conditions of the BSD License
   8   which accompanies this distribution.  The full text of the license may be found at
   9   http://opensource.org/licenses/bsd-license.php.
  10
  11   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  12   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  13
  14 **/
  15
  16 #ifndef _TCP_OPTION_H_
  17 #define _TCP_OPTION_H_
  18
  19 //
  20 // Supported TCP option types and their length.
  21 //
  22 #define TCP_OPTION_EOP             0  ///< End Of oPtion
  23 #define TCP_OPTION_NOP             1  ///< No-Option.
  24 #define TCP_OPTION_MSS             2  ///< Maximum Segment Size
  25 #define TCP_OPTION_WS              3  ///< Window scale
  26 #define TCP_OPTION_TS              8  ///< Timestamp
  27 #define TCP_OPTION_MSS_LEN         4  ///< Length of MSS option
  28 #define TCP_OPTION_WS_LEN          3  ///< Length of window scale option
  29 #define TCP_OPTION_TS_LEN          10 ///< Length of timestamp option
  30 #define TCP_OPTION_WS_ALIGNED_LEN  4  ///< Length of window scale option, aligned
  31 #define TCP_OPTION_TS_ALIGNED_LEN  12 ///< Length of timestamp option, aligned
  32
  33 //
  34 // recommend format of timestamp window scale
  35 // option for fast process.
  36 //
  37 #define TCP_OPTION_TS_FAST ((TCP_OPTION_NOP << 24) | \
  38                             (TCP_OPTION_NOP << 16) | \
  39                             (TCP_OPTION_TS << 8)   | \
  40                             (TCP_OPTION_TS_LEN))
  41
  42 #define TCP_OPTION_WS_FAST   ((TCP_OPTION_NOP << 24) | \
  43                               (TCP_OPTION_WS << 16)  | \
  44                               (TCP_OPTION_WS_LEN << 8))
  45
  46 #define TCP_OPTION_MSS_FAST  ((TCP_OPTION_MSS << 24) | (TCP_OPTION_MSS_LEN << 16))
  47
  48 //
  49 // Other misc definations
  50 //
  51 #define TCP_OPTION_RCVD_MSS        0x01
  52 #define TCP_OPTION_RCVD_WS         0x02
  53 #define TCP_OPTION_RCVD_TS         0x04
  54 #define TCP_OPTION_MAX_WS          14      ///< Maxium window scale value
  55 #define TCP_OPTION_MAX_WIN         0xffff  ///< Max window size in TCP header
  56
  57 ///
  58 /// The structure to store the parse option value.
  59 /// ParseOption only parses the options, doesn't process them.
  60 ///
  61 typedef struct _TCP_OPTION {
  62   UINT8   Flag;     ///< Flag such as TCP_OPTION_RCVD_MSS
  63   UINT8   WndScale; ///< The WndScale received
  64   UINT16  Mss;      ///< The Mss received
  65   UINT32  TSVal;    ///< The TSVal field in a timestamp option
  66   UINT32  TSEcr;    ///< The TSEcr field in a timestamp option
  67 } TCP_OPTION;
  68
  69 /**
  70   Compute the window scale value according to the given buffer size.
  71
  72   @param[in]  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[in]  Tcb     Pointer to the TCP_CB of this TCP instance.
  86   @param[in]  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[in]  Tcb     Pointer to the TCP_CB of this TCP instance.
 101   @param[in]  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[in]       Tcp     Pointer to the TCP_CB of this TCP instance.
 116   @param[in, out]  Option  Pointer to the TCP_OPTION used to store the
 117                            successfully pasrsed options.
 118
 119   @retval          0       The options 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[in]  Tcb     Pointer to the TCP_CB of this TCP instance.
 133   @param[in]  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