tcp.lst

RTL8019以太网开发板资料

C51 COMPILER V8.18   TCP                                                                   08/02/2010 19:52:46 PAGE 1   


C51 COMPILER V8.18, COMPILATION OF MODULE TCP
OBJECT MODULE PLACED IN TCP.OBJ
COMPILER INVOKED BY: C:\Keil\C51\BIN\C51.EXE TCP.C LARGE BROWSE DEBUG OBJECTEXTEND

line level    source

   1          //-----------------------------------------------------------------------------
   2          // Net TCP.C
   3          //
   4          // This module handles TCP segments
   5          // Refer to RFC 793, 896, 1122, 1323, 2018, 2581
   6          //
   7          // A "connection" is a unique combination of 4 items:  His IP address,
   8          // his port number, my IP address, and my port number.
   9          //
  10          // Note that a SYN and a FIN count as a byte of data, but a RST does
  11          // not count. Neither do any of the other flags.
  12          // See "TCP/IP Illustrated, Volume 1" Sect 17.3 for info on flags
  13          //-----------------------------------------------------------------------------
  14          #include <string.h>
  15          #include <stdlib.h>
  16          #include <ctype.h>              // toupper
  17          #include "main.h"               // toupper
  18          #include "udp.h"                // toupper
  19          #include "rs232.h"              // toupper
  20          #include "tcp.h"                // toupper
  21          #include "ip.h"         // toupper
  22          #include "ARP.h"                // toupper
  23          UWORK8 idata just_closed; // Keeps track of when a conxn closed
  24          // These structures keep track of connection information
  25          Str_CONNECTION xdata StrConnection_buf[2];        //设置可以同时接收5组IP地址的TCP数据
  26          UWORK32 initial_sequence_nr;                             //序列号
  27          UWORK8 TcpStateFlag;                            //TCP的状态标志位,是在各个过程中的状态 
  28          char xdata text[];
  29          // Options: MSS (4 bytes), NOPS (2 bytes), Selective ACK (2 bytes) 
  30          UWORK8 code options_buf[10] = {0x02, 0x04, 0x05, 0xB4, 0x01, 0x01, 0x04, 0x02};
  31          UWORK8 code optionsRe_buf[4] = {0x02, 0x04, 0x05, 0x78};          //建立连接的TCP选项
  32          
  33          UWORK8 HttpSendFlag;            //TCP有发送的数据
  34          
  35          //------------------------------------------------------------------------
  36          //  Initialize variables declared in this module
  37          //
  38          //------------------------------------------------------------------------
  39          /*********************************************************************
  40          函数名:       void init_tcp(void)
  41          功能:         初始化TCP的接收缓存器
  42          输入:         None 
  43          输出:         None
  44          返回:         None
  45          日期:         2004/02/04
  46          *********************************************************************/
  47          void init_tcp(void)
  48          {
  49   1         memset(StrConnection_buf, 0, sizeof(StrConnection_buf));
  50   1         just_closed = FALSE;
  51   1         initial_sequence_nr = 1;
  52   1      }
  53          //------------------------------------------------------------------------
  54          // This runs every 0.5 seconds.  If the connection has had no activity
  55          // it initiates closing the connection.
C51 COMPILER V8.18   TCP                                                                   08/02/2010 19:52:46 PAGE 2   

  56          //
  57          //------------------------------------------------------------------------
  58          /*********************************************************************
  59          函数名:       void tcp_inactivity(void)
  60          功能:         判断TCP的状态
  61          输入:         None 
  62          输出:         None
  63          返回:         None
  64          日期:         2004/02/04
  65          This runs every 0.5 seconds.  If the connection has had no activity
  66          // it initiates closing the connection.
  67          *********************************************************************/
  68          //------------------------------------------------------------------------
  69          // This runs every 0.5 seconds.  If the connection has had no activity
  70          // it initiates closing the connection.
  71          //
  72          //------------------------------------------------------------------------
  73          /*
  74          void tcp_inactivity(void)
  75          {
  76             UWORK8 idata nr;
  77             // Look for active connections in the established state
  78             for (nr = 0; nr < 2; nr++)
  79             {
  80                if ((StrConnection_buf[nr].ipaddr != 0) && (StrConnection_buf[nr].state == STATE_ESTABLISHED) && (St
             -rConnection_buf[nr].inactivity))
  81                {
  82                   // Decrement the timer and see if it hit 0
  83                   StrConnection_buf[nr].inactivity--;
  84                   if (StrConnection_buf[nr].inactivity == 0)
  85                   {
  86                      tcp_ReBack((FLG_ACK | FLG_FIN), 20, nr);
  87                                  StrConnection_buf[nr].My_SERIESNUM++;    // For my FIN
  88                      StrConnection_buf[nr].state = STATE_FIN_WAIT_1;
  89           //           if (debug) serial_send("TCP: Entered FIN_WAIT_1 state\r");        
  90                   }
  91                }
  92             }
  93          }
  94          */
  95          //------------------------------------------------------------------------
  96          // This runs every 0.5 seconds.  If the other end has not ACK'd
  97          // everyting we have sent, it re-sends it.  To save RAM space, we 
  98          // regenerate a segment rather than keeping a bunch of segments 
  99          // hanging around eating up RAM.  A connection should not be in an
 100          // opening or closing state when this timer expires, so we simply
 101          // send a reset.
 102          //
 103          //      If a connection is in the ESTABLISHED state when the timer expires
 104          // then we have just sent a web page so re-send the page
 105          //------------------------------------------------------------------------
 106          /*
 107          void tcp_retransmit(void)
 108          {
 109             UWORK8 idata retries = 0;
 110             UWORK8 idata nr;
 111          
 112                  // Scan through all active connections 
 113                  for (nr = 0; nr < 2; nr++)
 114                  {
 115                          if ((StrConnection_buf[nr].ipaddr != 0) && (StrConnection_buf[nr].timer))
 116                          {
C51 COMPILER V8.18   TCP                                                                   08/02/2010 19:52:46 PAGE 3   

 117                                  // Decrement the timer and see if it hit 0
 118                                  StrConnection_buf[nr].timer--;
 119                                  if (StrConnection_buf[nr].timer == 0)
 120                                  {
 121                                          // Socket just timed out. If we are not in ESTABLISHED state
 122                                          // something is amiss so send reset and close connection
 123                                          if (StrConnection_buf[nr].state != STATE_ESTABLISHED)