;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; ;;
;; Copyright (C) KolibriOS team 2004-2024. 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 ;;
;; ;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
align 4
iglobal
TCP_backoff db 0,1,2,3,4,5,6,6,6,6,6,6,6
endg
macro tcp_checksum IP1, IP2 {
;-------------
; Pseudoheader
; protocol type
mov edx, IP_PROTO_TCP
; source address
add dl, byte [IP1+1]
adc dh, byte [IP1+0]
adc dl, byte [IP1+3]
adc dh, byte [IP1+2]
; destination address
adc dl, byte [IP2+1]
adc dh, byte [IP2+0]
adc dl, byte [IP2+3]
adc dh, byte [IP2+2]
; size
adc dl, cl
adc dh, ch
adc edx, 0
;---------------------
; Real header and data
push esi
call checksum_1
call checksum_2
pop esi
} ; returns in dx only
macro tcp_sendseqinit ptr {
push edi ;;;; FIXME: i dont like this static use of edi
mov edi, [ptr + TCP_SOCKET.ISS]
mov [ptr + TCP_SOCKET.SND_UP], edi
mov [ptr + TCP_SOCKET.SND_MAX], edi
mov [ptr + TCP_SOCKET.SND_NXT], edi
mov [ptr + TCP_SOCKET.SND_UNA], edi
pop edi
}
macro tcp_rcvseqinit ptr {
push edi
mov edi, [ptr + TCP_SOCKET.IRS]
inc edi ; SYN ocupies a sequence number
mov [ptr + TCP_SOCKET.RCV_NXT], edi
mov [ptr + TCP_SOCKET.RCV_ADV], edi
pop edi
}
macro tcp_init_socket socket {
; new tcp control block
mov [socket + TCP_SOCKET.t_maxseg], TCP_mss_default
mov [socket + TCP_SOCKET.t_flags], TF_REQ_SCALE or TF_REQ_TSTMP
mov [socket + TCP_SOCKET.t_srtt], TCP_time_srtt_default
mov [socket + TCP_SOCKET.t_rttvar], TCP_time_rtt_default * 4
mov [socket + TCP_SOCKET.t_rttmin], TCP_time_re_min
;;; TODO: TCP_time_rangeset
mov [socket + TCP_SOCKET.SND_CWND], TCP_max_win shl TCP_max_winshift
mov [socket + TCP_SOCKET.SND_SSTHRESH], TCP_max_win shl TCP_max_winshift
mov [socket + TCP_SOCKET.RCV_SCALE], 0
mov [socket + TCP_SOCKET.SND_SCALE], 0
}
;-----------------------------------------------------------------;
; ;
; tcp_pull_out_of_band ;
; ;
; IN: eax = ? ;
; ebx = socket ptr ;
; edx = tcp packet ptr ;
; ;
; OUT: / ;
; ;
;-----------------------------------------------------------------;
align 4
tcp_pull_out_of_band:
DEBUGF DEBUG_NETWORK_VERBOSE, "tcp_pull_out_of_band\n"
;;;; 1282-1305
ret
;-----------------------------------------------------------------;
; ;
; tcp_drop ;
; ;
; IN: eax = socket ptr ;
; ebx = error number ;
; ;
; OUT: eax = socket ptr ;
; ;
;-----------------------------------------------------------------;
align 4
tcp_drop:
;;; TODO: check if error code is "Connection timed out' and handle accordingly
DEBUGF DEBUG_NETWORK_VERBOSE, "tcp_drop: %x\n", eax
cmp [eax + TCP_SOCKET.t_state], TCPS_SYN_RECEIVED
jb .no_syn_received
mov [eax + TCP_SOCKET.t_state], TCPS_CLOSED
push eax
call tcp_output
pop eax
inc [TCPS_drops]
mov [eax + SOCKET.errorcode], ebx
jmp tcp_close
.no_syn_received:
inc [TCPS_conndrops]
mov [eax + SOCKET.errorcode], ebx
jmp tcp_close
;-----------------------------------------------------------------;
; ;
; tcp_disconnect ;
; ;
; IN: eax = socket ptr ;
; ;
; OUT: eax = socket ptr / 0 ;
; ;
;-----------------------------------------------------------------;
align 4
tcp_disconnect:
DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_disconnect: %x\n", eax
cmp [eax + TCP_SOCKET.t_state], TCPS_ESTABLISHED
jb tcp_close ; Connection not yet synchronised, just get rid of the socket
test [eax + SOCKET.options], SO_LINGER
jz .nolinger
; TODO: implement LINGER
; cmp [eax + SOCKET.so_linger], 0
; je TCP_drop
.nolinger:
call socket_is_disconnecting
push eax
add eax, STREAM_SOCKET.rcv
mov ecx, [eax + RING_BUFFER.size]
call socket_ring_free
pop eax
call tcp_usrclosed
test eax, eax
jz @f
push eax
call tcp_output
pop eax
@@:
ret
;-----------------------------------------------------------------;
; ;
; tcp_close ;
; ;
; IN: eax = socket ptr ;
; ;
; OUT: / ;
; ;
;-----------------------------------------------------------------;
align 4
tcp_close:
DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_close: %x\n", eax
;;; TODO: update RTT and mean deviation
;;; TODO: update slow start threshold
call socket_is_disconnected
call socket_free
inc [TCPS_closed]
xor eax, eax
ret
;-----------------------------------------------------------------;
; ;
; tcp_outflags ;
; ;
; IN: eax = socket ptr ;
; ;
; OUT: edx = flags ;
; ;
;-----------------------------------------------------------------;
align 4
tcp_outflags:
mov edx, [eax + TCP_SOCKET.t_state]
movzx edx, byte[edx + .flaglist]
DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_outflags: socket=%x flags=%x\n", eax, dl
ret
.flaglist:
db TH_RST + TH_ACK ; TCPS_CLOSED
db 0 ; TCPS_LISTEN
db TH_SYN ; TCPS_SYN_SENT
db TH_SYN + TH_ACK ; TCPS_SYN_RECEIVED
db TH_ACK ; TCPS_ESTABLISHED
db TH_ACK ; TCPS_CLOSE_WAIT
db TH_FIN + TH_ACK ; TCPS_FIN_WAIT_1
db TH_FIN + TH_ACK ; TCPS_CLOSING
db TH_FIN + TH_ACK ; TCPS_LAST_ACK
db TH_ACK ; TCPS_FIN_WAIT_2
db TH_ACK ; TCPS_TIME_WAIT
;-----------------------------------------------------------------;
; ;
; TCP_respond: Fast way to send an ACK/RST/keepalive segment. ;
; ;
; IN: ebx = socket ptr ;
; cl = flags ;
; ;
; OUT: / ;
; ;
;-----------------------------------------------------------------;
align 4
tcp_respond:
DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_respond_socket: socket=%x flags=%x\n", ebx, cl
;---------------------
; Create the IP packet
push cx ebx
mov edx, [ebx + IP_SOCKET.LocalIP]
mov edi, [ebx + IP_SOCKET.RemoteIP]
mov al, [ebx + IP_SOCKET.ttl]
mov ah, IP_PROTO_TCP
mov ecx, sizeof.TCP_header
mov ebx, [ebx + IP_SOCKET.device]
call ipv4_output
jz .error
pop esi cx
push eax
;-----------------------------------------------
; Fill in the TCP header by using the socket ptr
mov ax, [esi + TCP_SOCKET.LocalPort]
stosw
mov ax, [esi + TCP_SOCKET.RemotePort]
stosw
mov eax, [esi + TCP_SOCKET.SND_NXT]
bswap eax
stosd
mov eax, [esi + TCP_SOCKET.RCV_NXT]
bswap eax
stosd
mov al, 0x50 ; Dataoffset: 20 bytes (TCP_header.DataOffset)
stosb
mov al, cl
stosb
mov eax, SOCKET_BUFFER_SIZE
sub eax, [esi + STREAM_SOCKET.rcv.size]
cmp eax, TCP_max_win
jbe .lessthanmax
mov eax, TCP_max_win
.lessthanmax:
mov cl, [esi + TCP_SOCKET.RCV_SCALE]
shr eax, cl
xchg al, ah
stosw ; window
xor eax, eax
stosd ; checksum + urgentpointer
;---------------------
; Fill in the checksum
.checksum:
sub edi, sizeof.TCP_header
mov ecx, sizeof.TCP_header
xchg esi, edi
tcp_checksum (edi + IP_SOCKET.LocalIP), (edi + IP_SOCKET.RemoteIP)
mov [esi+TCP_header.Checksum], dx
;--------------------
; And send the segment
call [ebx + NET_DEVICE.transmit]
test eax, eax
jnz @f
call net_ptr_to_num4
inc [TCP_segments_tx + edi]
@@:
ret
.error:
DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_respond_socket: failed\n"
add esp, 2 + 4
ret
;-----------------------------------------------------------------;
; ;
; tcp_respond_segment ;
; ;
; IN: ebx = device ptr ;
; edx = segment ptr (a previously received segment) ;
; edi = ptr to IPv4 header ;
; cl = flags ;
; ;
; OUT: / ;
; ;
;-----------------------------------------------------------------;
align 4
tcp_respond_segment:
DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_respond_segment: frame=%x flags=%x\n", edx, cl
;---------------------
; Create the IP packet
push cx edx
mov edx, [edi + IPv4_header.DestinationAddress]
mov edi, [edi + IPv4_header.SourceAddress]
mov ecx, sizeof.TCP_header
mov ax, IP_PROTO_TCP shl 8 + 128
call ipv4_output
jz .error
pop esi cx
push eax
;---------------------------------------------------
; Fill in the TCP header by using a received segment
mov ax, [esi + TCP_header.DestinationPort]
stosw
mov ax, [esi + TCP_header.SourcePort]
stosw
mov eax, [esi + TCP_header.AckNumber]
bswap eax
stosd
xor eax, eax
stosd
mov al, 0x50 ; Dataoffset: 20 bytes (sizeof.TCP_header/4 shl 4)
stosb
mov al, cl
stosb
mov ax, 1280
rol ax, 8
stosw ; window
xor eax, eax
stosd ; checksum + urgentpointer
;---------------------
; Fill in the checksum
lea esi, [edi - sizeof.TCP_header]
mov ecx, sizeof.TCP_header
tcp_checksum (esi - sizeof.IPv4_header + IPv4_header.DestinationAddress),\ ; FIXME
(esi - sizeof.IPv4_header + IPv4_header.SourceAddress)
mov [esi + TCP_header.Checksum], dx
;--------------------
; And send the segment
call [ebx + NET_DEVICE.transmit]
test eax, eax
jnz @f
call net_ptr_to_num4
inc [TCP_segments_tx + edi]
@@:
ret
.error:
DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_respond_segment: failed\n"
add esp, 2+4
ret
macro tcpt_rangeset timer, value, min, max {
local .min
local .max
local .done
cmp value, min
jb .min
cmp value, max
ja .max
mov timer, value
jmp .done
.min:
mov timer, min
jmp .done
.max:
mov timer, max
.done:
}
;-----------------------------------------------------------------;
; ;
; tcp_set_persist ;
; ;
;-----------------------------------------------------------------;
align 4
tcp_set_persist:
DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_set_persist\n"
; First, check if retransmit timer is not set, retransmit and persist are mutually exclusive
test [eax + TCP_SOCKET.timer_flags], timer_flag_retransmission
jnz .exit
; calculate RTO
push ebx
mov ebx, [eax + TCP_SOCKET.t_srtt]
shr ebx, 2
add ebx, [eax + TCP_SOCKET.t_rttvar]
shr ebx, 1
mov cl, [eax + TCP_SOCKET.t_rxtshift]
shl ebx, cl
; Start/restart persistance timer.
tcpt_rangeset [eax + TCP_SOCKET.timer_persist], ebx, TCP_time_pers_min, TCP_time_pers_max
or [ebx + TCP_SOCKET.timer_flags], timer_flag_persist
pop ebx
cmp [eax + TCP_SOCKET.t_rxtshift], TCP_max_rxtshift
jae @f
inc [eax + TCP_SOCKET.t_rxtshift]
@@:
.exit:
ret
;-----------------------------------------------------------------;
; ;
; tcp_xmit_timer: Calculate new smoothed RTT. ;
; ;
; IN: eax = rtt ;
; ebx = socket ptr ;
; ;
; OUT: / ;
; ;
;-----------------------------------------------------------------;
align 4
tcp_xmit_timer:
DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_xmit_timer: socket=0x%x rtt=%d0ms\n", ebx, eax
inc [TCPS_rttupdated]
cmp [ebx + TCP_SOCKET.t_rtt], 0
je .no_rtt_yet
; srtt is stored as a fixed point with 3 bits after the binary point.
; The following magic is equivalent of the smoothing algorithm in rfc793 with an alpha of .875
; (srtt = rtt/8 + srtt*7/8 in fixed point)
; Adjust rtt to origin 0.
push ecx
mov ecx, [ebx + TCP_SOCKET.t_srtt]
shr ecx, TCP_RTT_SHIFT
sub eax, ecx
dec eax
pop ecx
add [ebx + TCP_SOCKET.t_srtt], eax
ja @f
mov [ebx + TCP_SOCKET.t_srtt], 1
@@:
; We accumulate a smoothed rtt variance (actually, a smoothed mean difference),
; then set the retransmit timer to smoothed rtt + 4 times the smoothed variance.
; rttvar is stored as fixed point with 2 bits after the binary point.
; The following is equivalent to rfc793 smoothing with an alpha of .75
; (rttvar = rttvar*3/4 + delta/4) (delta = eax)
; get abs(eax)
push edx
cdq
xor eax, edx
sub eax, edx
mov edx, [ebx + TCP_SOCKET.t_rttvar]
shr edx, TCP_RTTVAR_SHIFT
sub eax, edx
pop edx
add [ebx + TCP_SOCKET.t_rttvar], eax
ja @f
mov [ebx + TCP_SOCKET.t_rttvar], 1
@@:
ret
.no_rtt_yet:
push ecx
mov ecx, eax
shl ecx, TCP_RTT_SHIFT
mov [ebx + TCP_SOCKET.t_srtt], ecx
shl eax, TCP_RTTVAR_SHIFT - 1
mov [ebx + TCP_SOCKET.t_rttvar], eax
pop ecx
ret
;-----------------------------------------------------------------;
; ;
; tcp_mss: Update maximum segment size ;
; ;
; IN: eax = max segment size ;
; ebx = socket ptr ;
; ;
; OUT: / ;
; ;
;-----------------------------------------------------------------;
align 4
tcp_mss:
cmp eax, 1420 ; FIXME
jbe @f
mov eax, 1420
@@:
mov [ebx + TCP_SOCKET.t_maxseg], eax
ret
;-----------------------------------------------------------------;
; ;
; tcp_reassemble ;
; ;
; IN: ebx = socket ptr ;
; edx = segment ptr ;
; ;
; OUT: / ;
; ;
;-----------------------------------------------------------------;
align 4
tcp_reassemble:
;;;;; TODO
ret