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      1 /** @file
      2   Tcp option's routine header file.
      3 
      4 Copyright (c) 2005 - 2009, 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
    146