kolibrios-gitea/kernel/branches/net/network/tcp.inc

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;;                                                                 ;;
;; Copyright (C) KolibriOS team 2004-2013. All rights reserved.    ;;
;; Distributed under terms of the GNU General Public License       ;;
;;                                                                 ;;
;;  Part of the TCP/IP network stack for KolibriOS                 ;;
;;                                                                 ;;
;;   Written by hidnplayr@kolibrios.org                            ;;
;;                                                                 ;;
;;    Based on the code of 4.4BSD                                  ;;
;;                                                                 ;;
;;          GNU GENERAL PUBLIC LICENSE                             ;;
;;             Version 2, June 1991                                ;;
;;                                                                 ;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

$Revision$

; Socket states
TCPS_CLOSED             = 0
TCPS_LISTEN             = 1
TCPS_SYN_SENT           = 2
TCPS_SYN_RECEIVED       = 3
TCPS_ESTABLISHED        = 4
TCPS_CLOSE_WAIT         = 5
TCPS_FIN_WAIT_1         = 6
TCPS_CLOSING            = 7
TCPS_LAST_ACK           = 8
TCPS_FIN_WAIT_2         = 9
TCPS_TIMED_WAIT         = 10

; Socket Flags
TF_ACKNOW               = 1 shl 0     ; ack peer immediately
TF_DELACK               = 1 shl 1     ; ack, but try to delay it
TF_NODELAY              = 1 shl 2     ; don't delay packets to coalesce
TF_NOOPT                = 1 shl 3     ; don't use tcp options
TF_SENTFIN              = 1 shl 4     ; have sent FIN
TF_REQ_SCALE            = 1 shl 5     ; have/will request window scaling
TF_RCVD_SCALE           = 1 shl 6     ; other side has requested scaling
TF_REQ_TSTMP            = 1 shl 7     ; have/will request timestamps
TF_RCVD_TSTMP           = 1 shl 8     ; a timestamp was received in SYN
TF_SACK_PERMIT          = 1 shl 9     ; other side said I could SACK

; Segment flags
TH_FIN                  = 1 shl 0
TH_SYN                  = 1 shl 1
TH_RST                  = 1 shl 2
TH_PUSH                 = 1 shl 3
TH_ACK                  = 1 shl 4
TH_URG                  = 1 shl 5

; Segment header options
TCP_OPT_EOL             = 0           ; End of option list.
TCP_OPT_NOP             = 1           ; No-Operation.
TCP_OPT_MAXSEG          = 2           ; Maximum Segment Size.
TCP_OPT_WINDOW          = 3           ; window scale
TCP_OPT_SACK_PERMIT     = 4           ; Selective Acknowledgement
TCP_OPT_SACK            = 5
TCP_OPT_TIMESTAMP       = 8

; Fundamental timer values
TCP_time_MSL            = 47          ; max segment lifetime (30s)
TCP_time_re_min         = 2           ; min retransmission (1,28s)
TCP_time_re_max         = 100         ; max retransmission (64s)
TCP_time_pers_min       = 8           ; min persist (5,12s)
TCP_time_pers_max       = 94          ; max persist (60,16s)
TCP_time_keep_init      = 118         ; connection establishment (75,52s)
TCP_time_keep_idle      = 4608        ; idle time before 1st probe (2h)
TCP_time_keep_interval  = 118         ; between probes when no response (75,52s)
TCP_time_rtt_default    = 5           ; default Round Trip Time (3,2s)
TCP_time_srtt_default   = 0           ;
TCP_time_max_idle       = 8*TCP_time_keep_interval      ; FIXME

; timer constants
TCP_max_rxtshift        = 12          ; max retransmissions waiting for ACK
TCP_max_keepcnt         = 8           ; max keepalive probes

;
TCP_max_winshift        = 14
TCP_max_win             = 65535

TCP_re_xmit_thresh      = 3

TCP_mss_default         = 1480        ; default max segment size

; smoothed round trip time and estimated variance are stored as fixed point numbers,
; shifted by the value below.
; With these scales, srtt has 3 bits to the right of the binary point, and thus an "alpha"
; of .875. rttvar has 2 bits to the right and thus "alpha" of 0.75
TCP_RTT_SHIFT           = 3
TCP_RTTVAR_SHIFT        = 2

; bits used by tcp_input and tcp_output
TCP_BIT_NEEDOUTPUT      = 1 shl 0
TCP_BIT_TIMESTAMP       = 1 shl 1
TCP_BIT_DROPSOCKET      = 1 shl 2

TCP_BIT_SENDALOT        = 1 shl 0

TCP_PAWS_IDLE           = 24*24*60*60*100       ; 24 days, in 1/100 seconds

TCP_QUEUE_SIZE          = 50

struct  TCP_header

        SourcePort              dw ?
        DestinationPort         dw ?
        SequenceNumber          dd ?
        AckNumber               dd ?
        DataOffset              db ?    ; DataOffset[0-3 bits] and Reserved[4-7]
        Flags                   db ?    ; Reserved[0-1 bits]|URG|ACK|PSH|RST|SYN|FIN
        Window                  dw ?
        Checksum                dw ?
        UrgentPointer           dw ?

ends

struct  TCP_queue_entry

        ip_ptr          dd ?
        segment_ptr     dd ?
        segment_size    dd ?
        device_ptr      dd ?

        buffer_ptr      dd ?
        buffer_size     dd ?

ends

align 4
uglobal
        TCP_segments_tx         rd MAX_NET_DEVICES
        TCP_segments_rx         rd MAX_NET_DEVICES
        TCP_segments_missed     rd MAX_NET_DEVICES
        TCP_segments_dumped     rd MAX_NET_DEVICES
;        TCP_bytes_rx            rq MAX_NET_DEVICES
;        TCP_bytes_tx            rq MAX_NET_DEVICES
        TCP_sequence_num        dd ?
        TCP_queue               rd TCP_QUEUE_SIZE*sizeof.TCP_queue_entry/4
endg


;-----------------------------------------------------------------
;
; TCP_init
;
;  This function resets all TCP variables
;
;-----------------------------------------------------------------
macro   TCP_init {

        xor     eax, eax
        mov     edi, TCP_segments_tx
        mov     ecx, (6*MAX_NET_DEVICES)
        rep     stosd

        pseudo_random   eax
        mov     [TCP_sequence_num], eax

        init_queue TCP_queue

}


include 'tcp_timer.inc'
include 'tcp_subr.inc'
include 'tcp_usreq.inc'
include 'tcp_input.inc'
include 'tcp_output.inc'


;---------------------------------------------------------------------------
;
; TCP_API
;
; This function is called by system function 76
;
; IN:  subfunction number in bl
;      device number in bh
;      ecx, edx, .. depends on subfunction
;
; OUT:
;
;---------------------------------------------------------------------------
align 4
TCP_api:

        movzx   eax, bh
        shl     eax, 2

        test    bl, bl
        jz      .packets_tx     ; 0
        dec     bl
        jz      .packets_rx     ; 1
        dec     bl
        jz      .packets_missed ; 2
        dec     bl
        jz      .packets_dumped ; 3

  .error:
        mov     eax, -1
        ret

  .packets_tx:
        mov     eax, [TCP_segments_tx + eax]
        ret

  .packets_rx:
        mov     eax, [TCP_segments_rx + eax]
        ret

  .packets_missed:
        mov     eax, [TCP_segments_missed + eax]
        ret

  .packets_dumped:
        mov     eax, [TCP_segments_dumped + eax]
        ret