📄 tcp.lst
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728 5 conxn[index].state = STATE_TIME_WAIT;
729 5 // if (debug) PrintStr("TCP: Entered TIME_WAIT state\r");
730 5
731 5 conxn[index].state = STATE_CLOSED;
C51 COMPILER V8.02 TCP 09/21/2006 20:16:32 PAGE 13
732 5 InerClose(index); // Free up connection
733 5 just_closed = TRUE;
734 5 }
735 4 else
736 4 {
737 5 // He has not ACK'd my FIN. This happens when there is a simultaneous
738 5 // close - I got his FIN but he has not yet ACK'd my FIN
739 5 conxn[index].state = STATE_CLOSING;
740 5 // if (debug) PrintStr("TCP: Entered CLOSING state\r");
741 5 }
742 4 }
743 3 else if (packACK == conxn[index].my_sequence)
744 3 {
745 4 // He has ACK'd my FIN but has not sent a FIN yet himself
746 4 conxn[index].state = STATE_FIN_WAIT_2;
747 4 // if (debug) PrintStr("TCP: Entered FIN_WAIT_2 state\r");
748 4 }
749 3 break;
750 3 case STATE_FIN_WAIT_2:
751 3 // He may still be sending me data - should process it
752 3 conxn[index].his_sequence += data_len;
753 3 conxn[index].his_ack = packACK;
754 3
755 3 if (pRxdnet->tcpframe.control & FLG_FIN)
756 3 {
757 4 conxn[index].his_sequence++; // For his FIN flag
758 4 tcp_send(&TCPSend,FLG_ACK, 20, index);
759 4 conxn[index].state = STATE_TIME_WAIT;
760 4 // if (debug) PrintStr("TCP: Entered TIME_WAIT state\r");
761 4 // conxn[index].state = STATE_CLOSED;
762 4 InerClose(index); // Free up struct area
763 4 just_closed = TRUE;
764 4 }
765 3 break;
766 3 case STATE_TIME_WAIT:
767 3 // With this code, should not get here
768 3 //因为在进入FIN_WAIT_2后这边的连接直接进入CLOSED
769 3 // if (debug) PrintStr("TCP: Oops! In TIME_WAIT state\r");
770 3 break;
771 3 case STATE_CLOSING:
772 3 // Simultaneous close has happened. I have received his FIN
773 3 // but he has not yet ACK'd my FIN. Waiting for ACK.
774 3 // Will not receive data in this state
775 3 conxn[index].his_ack = packACK;
776 3
777 3 if (packACK == conxn[index].my_sequence)
778 3 {
779 4 conxn[index].state = STATE_TIME_WAIT;
780 4 // if (debug) PrintStr("TCP: Entered TIME_WAIT state\r");
781 4
782 4 // Do not send any response to his ACK
783 4 // conxn[index].state = STATE_CLOSED;
784 4 InerClose(index); // Free up struct area
785 4 just_closed = TRUE;
786 4 }
787 3 break;
788 3 case STATE_SYN_SENT:
789 3 //这些代码用于当连接为客户端是的状况
790 3 //// If incoming segment contains SYN and ACK, then handle
791 3 if ((pRxdnet->tcpframe.control & FLG_SYN) && (pRxdnet->tcpframe.control & FLG_ACK))
792 3 {
793 4 conxn[index].my_sequence++; //for my SYN
C51 COMPILER V8.02 TCP 09/21/2006 20:16:32 PAGE 14
794 4 conxn[index].ip.words[0]= pRxdnet->ipframe.sourceip[0];
795 4 conxn[index].ip.words[1]= pRxdnet->ipframe.sourceip[1];
796 4 conxn[index].port = pRxdnet->tcpframe.sourceport;
797 4 conxn[index].localport=LOCAL_PORT;
798 4 conxn[index].state = STATE_ESTABLISHED;
799 4 conxn[index].socket_type = CLIENT;
800 4 conxn[index].his_sequence = 1 + packSeq;
801 4 conxn[index].his_ack = packACK;
802 4 tcp_send(&TCPSend,FLG_ACK, 20, index); // Send ACK
803 4 //调用OnConnect()函数
804 4 (* conxn[index].connect)();
805 4 }
806 3 break;
807 3 default:
808 3 // if (debug) PrintStr("TCP: Error, no handler\r");
809 3 break;
810 3 }
811 2 // This is for debug, to see when conxn closes
812 2 if (just_closed)
813 2 {
814 3 just_closed = FALSE;
815 3 if (debug) PrintStr("TCP: Closed connection ");
816 3 }
817 2
818 2 }
819 1 }
820
821
822
823 //------------------------------------------------------------------------
824 // This runs every 0.5 seconds. If the other end has not ACK'd
825 // everyting we have sent, it re-sends it. To save RAM space, we
826 // regenerate a segment rather than keeping a bunch of segments
827 // hanging around eating up RAM. A connection should not be in an
828 // opening or closing state when this timer expires, so we simply
829 // send a reset.
830 //
831 // If a connection is in the ESTABLISHED state when the timer expires
832 // then we have just sent a web page so re-send the page
833 //2006－02－13：修改重传的次数及时间
834 //------------------------------------------------------------------------
835 void tcp_retransmit()
836 {
837 1 unsigned char nr;
838 1 // Scan through all active connections
839 1 for (nr = 0; nr < NO_CONNECTION; nr++)
840 1 {
841 2 if ((conxn[nr].ip.dwords != 0) && (conxn[nr].timer))
842 2 {
843 3 // Decrement the timer and see if it hit 0
844 3 conxn[nr].timer--;
845 3 if (conxn[nr].timer == 0)
846 3 {
847 4
848 4 // Socket just timed out. If we are not in ESTABLISHED state
849 4 // something is amiss so send reset and close connection
850 4 if (conxn[nr].state != STATE_ESTABLISHED)
851 4 {
852 5 // Send reset and close connection
853 5 if (debug) PrintStr("TCP: Timeout, sending reset\r");
854 5 tcp_send(&TCPSend,FLG_RST, 20, nr);
855 5 InerClose(nr);
C51 COMPILER V8.02 TCP 09/21/2006 20:16:32 PAGE 15
856 5 return;
857 5 }
858 4 else
859 4 {
860 5 // Socket is in ESTABLISHED state. First make sure his
861 5 // ack number is not bogus.
862 5 if (conxn[nr].his_ack > conxn[nr].my_sequence)
863 5 {
864 6 // Send reset and close connection
865 6 if (debug) PrintStr("TCP: Timeout, sending reset2\r");
866 6 tcp_send(&TCPSend,FLG_RST, 20, nr);
867 6 InerClose(nr);
868 6 return;
869 6 }
870 5 // We always increment our sequence number immediately
871 5 // after sending, so the ack number from the other end
872 5 // should be equal to our sequence number. If it is less,
873 5 // it means he lost some of our data.
874 5 // if (conxn[nr].his_ack < conxn[nr].my_sequence)
875 5 // {
876 5 else
877 5 {
878 6 if(conxn[nr].pUnAcked->bUsed)
879 6 {
880 7 conxn[nr].retries++;
881 7 if (conxn[nr].retries <= RESENDCOUNT)
882 7 {
883 8 // The only thing we send is a web page, and it looks
884 8 // like other end did not get it, so resend
885 8 // but do not increase my sequence number
886 8 if (debug) PrintStr("TCP: Timeout, resending data\r");
887 8 tcp_senddata(&TCPSend,conxn[nr].pUnAcked->pBuf,conxn[nr].pUnAcked->iLen+20,nr,1);
888 8 //重置保活定时器
889 8 conxn[nr].aty_timer = INACTIVITY_TIME;
890 8 }
891 7 else
892 7 {
893 8 conxn[nr].retries = 0;
894 8 if (debug) PrintStr("TCP: Giving up, sending reset\r");
895 8 // Send reset and close connection
896 8 tcp_send(&TCPSend,FLG_RST, 20, nr);
897 8 InerClose(nr);
898 8 }
899 7 }
900 6 }
901 5 }
902 4 }
903 3 }
904 2 }
905 1 }
906
907
908
909
910 //------------------------------------------------------------------------
911 // 该函数每隔2个小时执行，向对方发送一个ARP请求，如果搜到arp echo，则接着发送
912 //一个ack，该ack序号为正常ack－1⌨️ 快捷键说明
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