WebSVN – Kolibri OS – Blame – /kernel/trunk/network/tcp_subr.inc

Rev	Author	Line No.	Line
3545	hidnplayr	1	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
		2	;; ;;
		3	;; Copyright (C) KolibriOS team 2004-2012. All rights reserved. ;;
		4	;; Distributed under terms of the GNU General Public License ;;
		5	;; ;;
		6	;; Part of the TCP/IP network stack for KolibriOS ;;
		7	;; ;;
		8	;; Written by hidnplayr@kolibrios.org ;;
		9	;; ;;
		10	;; Based on the code of 4.4BSD ;;
		11	;; ;;
		12	;; GNU GENERAL PUBLIC LICENSE ;;
		13	;; Version 2, June 1991 ;;
		14	;; ;;
		15	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
		16
		17	$Revision: 3514 $
		18
		19	align 4
		20	iglobal
		21	TCP_backoff db 0,1,2,3,4,5,6,6,6,6,6,6,6
		22	endg
		23
		24	macro TCP_checksum IP1, IP2 {
		25
		26	;-------------
		27	; Pseudoheader
		28
		29	; protocol type
		30	mov edx, IP_PROTO_TCP
		31
		32	; source address
		33	add dl, byte [IP1+1]
		34	adc dh, byte [IP1+0]
		35	adc dl, byte [IP1+3]
		36	adc dh, byte [IP1+2]
		37
		38	; destination address
		39	adc dl, byte [IP2+1]
		40	adc dh, byte [IP2+0]
		41	adc dl, byte [IP2+3]
		42	adc dh, byte [IP2+2]
		43
		44	; size
		45	adc dl, cl
		46	adc dh, ch
		47
		48	adc edx, 0
		49
		50	;---------------------
		51	; Real header and data
		52
		53	push esi
		54	call checksum_1
		55	call checksum_2
		56	pop esi
		57
		58	} ; returns in dx only
		59
		60
		61
		62
		63	macro TCP_sendseqinit ptr {
		64
		65	push edi ;;;; i dont like this static use of edi
		66	mov edi, [ptr + TCP_SOCKET.ISS]
		67	mov [ptr + TCP_SOCKET.SND_UP], edi
		68	mov [ptr + TCP_SOCKET.SND_MAX], edi
		69	mov [ptr + TCP_SOCKET.SND_NXT], edi
		70	mov [ptr + TCP_SOCKET.SND_UNA], edi
		71	pop edi
		72
		73	}
		74
		75
		76
		77	macro TCP_rcvseqinit ptr {
		78
		79	push edi
		80	mov edi, [ptr + TCP_SOCKET.IRS]
		81	inc edi
		82	mov [ptr + TCP_SOCKET.RCV_NXT], edi
		83	mov [ptr + TCP_SOCKET.RCV_ADV], edi
		84	pop edi
		85
		86	}
		87
		88
		89
		90	macro TCP_init_socket socket {
		91
		92	mov [socket + TCP_SOCKET.t_maxseg], TCP_mss_default
		93	mov [socket + TCP_SOCKET.t_flags], TF_REQ_SCALE or TF_REQ_TSTMP
		94
		95	mov [socket + TCP_SOCKET.t_srtt], TCP_time_srtt_default
		96	mov [socket + TCP_SOCKET.t_rttvar], TCP_time_rtt_default * 4
		97	mov [socket + TCP_SOCKET.t_rttmin], TCP_time_re_min
		98	;;; TODO: TCP_time_rangeset
		99
		100	mov [socket + TCP_SOCKET.SND_CWND], TCP_max_win shl TCP_max_winshift
		101	mov [socket + TCP_SOCKET.SND_SSTHRESH], TCP_max_win shl TCP_max_winshift
		102
		103
		104	}
		105
		106
		107	;---------------------------
		108	;
		109	; TCP_pull_out_of_band
		110	;
		111	; IN: eax =
		112	; ebx = socket ptr
		113	; edx = tcp packet ptr
		114	;
		115	; OUT: /
		116	;
		117	;---------------------------
		118
		119	align 4
		120	TCP_pull_out_of_band:
		121
		122	DEBUGF 1,"TCP_pull_out_of_band\n"
		123
		124	;;;; 1282-1305
		125
		126	ret
		127
		128
		129
		130
		131
		132
		133
		134
		135	;-------------------------
		136	;
		137	; TCP_drop
		138	;
		139	; IN: eax = socket ptr
		140	; ebx = error number
		141	;
		142	; OUT: eax = socket ptr
		143	;
		144	;-------------------------
		145	align 4
		146	TCP_drop:
		147
		148	DEBUGF 1,"TCP_drop: %x\n", eax
		149
		150	cmp [eax + TCP_SOCKET.t_state], TCPS_SYN_RECEIVED
		151	jb .no_syn_received
		152
		153	mov [eax + TCP_SOCKET.t_state], TCPS_CLOSED
		154
		155	call TCP_output
		156
		157	;;; TODO: update stats
		158
		159	jmp TCP_close
		160
		161	.no_syn_received:
		162
		163	;;; TODO: update stats
		164
		165	;;; TODO: check if error code is "Connection timed out' and handle accordingly
		166
		167	mov [eax + SOCKET.errorcode], ebx
		168
		169
		170
		171
		172
		173
		174
		175
		176	;-------------------------
		177	;
		178	; TCP_close
		179	;
		180	; IN: eax = socket ptr
		181	; OUT: eax = socket ptr
		182	;
		183	;-------------------------
		184	align 4
		185	TCP_close:
		186
		187	DEBUGF 1,"TCP_close: %x\n", eax
		188
		189	;;; TODO: update RTT and mean deviation
		190	;;; TODO: update slow start threshold
		191
		192	call SOCKET_is_disconnected
		193	call SOCKET_free
		194
		195	ret
		196
		197
		198
		199
		200	;-------------------------
		201	;
		202	; TCP_outflags
		203	;
		204	; IN: eax = socket ptr
		205	;
		206	; OUT: edx = flags
		207	;
		208	;-------------------------
		209	align 4
		210	TCP_outflags:
		211
		212	mov edx, [eax + TCP_SOCKET.t_state]
		213	movzx edx, byte [edx + .flaglist]
		214
		215	DEBUGF 1,"TCP_outflags: socket=%x flags=%x\n", eax, dl
		216
		217	ret
		218
		219	.flaglist:
		220
		221	db TH_RST + TH_ACK ; TCPS_CLOSED
		222	db 0 ; TCPS_LISTEN
		223	db TH_SYN ; TCPS_SYN_SENT
		224	db TH_SYN + TH_ACK ; TCPS_SYN_RECEIVED
		225	db TH_ACK ; TCPS_ESTABLISHED
		226	db TH_ACK ; TCPS_CLOSE_WAIT
		227	db TH_FIN + TH_ACK ; TCPS_FIN_WAIT_1
		228	db TH_FIN + TH_ACK ; TCPS_CLOSING
		229	db TH_FIN + TH_ACK ; TCPS_LAST_ACK
		230	db TH_ACK ; TCPS_FIN_WAIT_2
		231	db TH_ACK ; TCPS_TIMED_WAIT
		232
		233
		234
		235
		236
		237
		238	;---------------------------------------
		239	;
		240	; The fast way to send an ACK/RST/keepalive segment
		241	;
		242	; TCP_respond
		243	;
		244	; IN: ebx = socket ptr
		245	; cl = flags
		246	;
		247	;--------------------------------------
		248	align 4
		249	TCP_respond:
		250
		251	DEBUGF 1,"TCP_respond_socket: socket=%x flags=%x\n", ebx, cl
		252
		253	;---------------------
		254	; Create the IP packet
		255
		256	push cx ebx
		257	mov eax, [ebx + IP_SOCKET.RemoteIP]
		258	mov edx, [ebx + IP_SOCKET.LocalIP]
		259	mov ecx, sizeof.TCP_header
		260	mov di, IP_PROTO_TCP shl 8 + 128
		261	call IPv4_output
		262	test edi, edi
		263	jz .error
		264	pop esi cx
		265	push edx eax
		266
		267	;-----------------------------------------------
		268	; Fill in the TCP header by using the socket ptr
		269
		270	mov ax, [esi + TCP_SOCKET.LocalPort]
		271	stosw
		272	mov ax, [esi + TCP_SOCKET.RemotePort]
		273	stosw
		274	mov eax, [esi + TCP_SOCKET.SND_NXT]
		275	bswap eax
		276	stosd
		277	mov eax, [esi + TCP_SOCKET.RCV_NXT]
		278	bswap eax
		279	stosd
		280	mov al, 0x50 ; Dataoffset: 20 bytes (TCP_header.DataOffset)
		281	stosb
		282	mov al, cl
		283	stosb
		284	; mov ax, [esi + TCP_SOCKET.RCV_WND]
		285	; rol ax, 8
		286	mov ax, 0x00a0 ;;;;;;; FIXME
		287	stosw ; window
		288	xor eax, eax
		289	stosd ; checksum + urgentpointer
		290
		291	;---------------------
		292	; Fill in the checksum
		293
		294	.checksum:
		295	sub edi, sizeof.TCP_header
		296	mov ecx, sizeof.TCP_header
		297	xchg esi, edi
		298	TCP_checksum (edi + IP_SOCKET.LocalIP), (edi + IP_SOCKET.RemoteIP)
		299	mov [esi+TCP_header.Checksum], dx
		300
		301	;--------------------
		302	; And send the segment
		303
		304	call [ebx + NET_DEVICE.transmit]
		305	ret
		306
		307	.error:
		308	DEBUGF 1,"TCP_respond_socket: failed\n"
		309	add esp, 2 + 4
		310
		311	ret
		312
		313
		314
		315
		316
		317
		318
		319
		320	;-------------------------
		321	; TCP_respond_segment:
		322	;
		323	; IN: edx = segment ptr (a previously received segment)
		324	; edi = ptr to dest and src IPv4 addresses
		325	; cl = flags
		326
		327	align 4
		328	TCP_respond_segment:
		329
		330	DEBUGF 1,"TCP_respond_segment: frame=%x flags=%x\n", edx, cl
		331
		332	;---------------------
		333	; Create the IP packet
		334
		335	push cx edx
		336	mov ebx, [edi + 4]
		337	mov eax, [edi]
		338	mov ecx, sizeof.TCP_header
		339	mov di, IP_PROTO_TCP shl 8 + 128
		340	call IPv4_output
		341	jz .error
		342	pop esi cx
		343
		344	push edx eax
		345
		346	;---------------------------------------------------
		347	; Fill in the TCP header by using a received segment
		348
		349	mov ax, [esi + TCP_header.DestinationPort]
		350	stosw
		351	mov ax, [esi + TCP_header.SourcePort]
		352	stosw
		353	mov eax, [esi + TCP_header.AckNumber]
		354	bswap eax
		355	stosd
		356	xor eax, eax
		357	stosd
		358	mov al, 0x50 ; Dataoffset: 20 bytes (sizeof.TCP_header/4 shl 4)
		359	stosb
		360	mov al, cl
		361	stosb
		362	mov ax, 1280
		363	rol ax, 8
		364	stosw ; window
		365	xor eax, eax
		366	stosd ; checksum + urgentpointer
		367
		368	;---------------------
		369	; Fill in the checksum
		370
		371	lea esi, [edi - sizeof.TCP_header]
		372	mov ecx, sizeof.TCP_header
		373	TCP_checksum (esi - sizeof.IPv4_header + IPv4_header.DestinationAddress),\ ; FIXME
		374	(esi - sizeof.IPv4_header + IPv4_header.SourceAddress)
		375	mov [esi + TCP_header.Checksum], dx
		376
		377	;--------------------
		378	; And send the segment
		379
		380	call [ebx + NET_DEVICE.transmit]
		381	ret
		382
		383	.error:
		384	DEBUGF 1,"TCP_respond_segment: failed\n"
		385	add esp, 2+4
		386
		387	ret
		388
		389
		390	macro TCPT_RANGESET timer, value, min, max {
		391
		392	local .min
		393	local .max
		394	local .done
		395
		396	cmp value, min
		397	jb .min
		398	cmp value, max
		399	ja .max
		400
		401	mov timer, value
		402	jmp .done
		403
		404	.min:
		405	mov timer, value
		406	jmp .done
		407
		408	.max:
		409	mov timer, value
		410	jmp .done
		411
		412	.done:
		413	}
		414
		415
		416	align 4
		417	TCP_set_persist:
		418
		419	DEBUGF 1,"TCP_set_persist\n"
		420
		421	; First, check if retransmit timer is not set, retransmit and persist are mutually exclusive
		422
		423	cmp [eax + TCP_SOCKET.timer_retransmission], 0
		424	ja @f
		425
		426	; calculate RTO
		427	push ebx
		428	mov ebx, [eax + TCP_SOCKET.t_srtt]
		429	shr ebx, 2
		430	add ebx, [eax + TCP_SOCKET.t_rttvar]
		431	shr ebx, 1
		432
		433	mov cl, [eax + TCP_SOCKET.t_rxtshift]
		434	shl ebx, cl
		435
		436	; Start/restart persistance timer.
		437
		438	TCPT_RANGESET [eax + TCP_SOCKET.timer_persist], ebx, TCP_time_pers_min, TCP_time_pers_max
		439
		440	pop ebx
		441
		442	cmp [eax + TCP_SOCKET.t_rxtshift], TCP_max_rxtshift
		443	jae @f
		444	inc [eax + TCP_SOCKET.t_rxtshift]
		445	@@:
		446
		447	ret
		448
		449
		450
		451	; eax = rtt
		452	; ebx = socket ptr
		453
		454	align 4
		455	TCP_xmit_timer:
		456
		457	DEBUGF 1,"TCP_xmit_timer: socket=%x rtt=%d0ms\n", ebx, eax
		458
		459	;TODO: update stats
		460
		461	cmp [ebx + TCP_SOCKET.t_rtt], 0
		462	je .no_rtt_yet
		463
		464	; srtt is stored as a fixed point with 3 bits after the binary point.
		465	; The following magic is equivalent of the smoothing algorithm in rfc793 with an alpha of .875
		466	; (srtt = rtt/8 + srtt*7/8 in fixed point)
		467	; Adjust rtt to origin 0.
		468
		469	push ecx
		470	mov ecx, [ebx + TCP_SOCKET.t_srtt]
		471	shr ecx, TCP_RTT_SHIFT
		472	sub eax, ecx
		473	dec eax
		474	pop ecx
		475
		476	add [ebx + TCP_SOCKET.t_srtt], eax
		477	ja @f
		478	mov [ebx + TCP_SOCKET.t_srtt], 1
		479	@@:
		480
		481	; We accumulate a smoothed rtt variance (actually, a smoothed mean difference),
		482	; then set the retransmit timer to smoothed rtt + 4 times the smoothed variance.
		483	; rttvar is stored as fixed point with 2 bits after the binary point.
		484	; The following is equivalent to rfc793 smoothing with an alpha of .75
		485	; (rttvar = rttvar*3/4 + delta/4) (delta = eax)
		486
		487	; get abs(eax)
		488	push edx
		489	cdq
		490	xor eax, edx
		491	sub eax, edx
		492
		493	mov edx, [ebx + TCP_SOCKET.t_rttvar]
		494	shr edx, TCP_RTTVAR_SHIFT
		495	sub eax, edx
		496	pop edx
		497
		498	add [ebx + TCP_SOCKET.t_rttvar], eax
		499	ja @f
		500	mov [ebx + TCP_SOCKET.t_rttvar], 1
		501	@@:
		502	ret
		503
		504
		505	.no_rtt_yet:
		506
		507	push ecx
		508	mov ecx, eax
		509	shl ecx, TCP_RTT_SHIFT
		510	mov [ebx + TCP_SOCKET.t_srtt], ecx
		511
		512	shl eax, TCP_RTTVAR_SHIFT - 1
		513	mov [ebx + TCP_SOCKET.t_rttvar], eax
		514	pop ecx
		515
		516	ret
		517
		518
		519
		520
		521	; eax = max segment size
		522	; ebx = socket ptr
		523	align 4
		524	TCP_mss:
		525
		526	cmp eax, 1420 ; FIXME
		527	jbe @f
		528	mov eax, 1420
		529	@@:
		530	mov [ebx + TCP_SOCKET.t_maxseg], eax
		531
		532
		533	ret
		534
		535
		536
		537
		538	; ebx = socket ptr
		539	; edx = segment ptr
		540	align 4
		541	TCP_reassemble:
		542
		543
		544
		545	ret
		546

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