WebSVN – Kolibri OS – Blame – /kernel/branches/net/network/tcp.inc

Rev	Author	Line No.	Line
1196	hidnplayr	1	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
		2	;; ;;
1514	hidnplayr	3	;; Copyright (C) KolibriOS team 2004-2010. All rights reserved. ;;
1196	hidnplayr	4	;; Distributed under terms of the GNU General Public License ;;
		5	;; ;;
		6	;; TCP.INC ;;
		7	;; ;;
		8	;; Part of the tcp/ip network stack for KolibriOS ;;
		9	;; ;;
1514	hidnplayr	10	;; Written by hidnplayr@kolibrios.org ;;
1196	hidnplayr	11	;; ;;
1514	hidnplayr	12	;; Based on the code of 4.4BSD ;;
		13	;; ;;
1196	hidnplayr	14	;; GNU GENERAL PUBLIC LICENSE ;;
		15	;; Version 2, June 1991 ;;
		16	;; ;;
		17	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
1159	hidnplayr	18
1206	hidnplayr	19	$Revision: 1536 $
1159	hidnplayr	20
1514	hidnplayr	21	; Socket states
		22	TCB_CLOSED equ 0
		23	TCB_LISTEN equ 1
		24	TCB_SYN_SENT equ 2
		25	TCB_SYN_RECEIVED equ 3
		26	TCB_ESTABLISHED equ 4
		27	TCB_CLOSE_WAIT equ 5
		28	TCB_FIN_WAIT_1 equ 6
		29	TCB_CLOSING equ 7
		30	TCB_LAST_ACK equ 8
		31	TCB_FIN_WAIT_2 equ 9
		32	TCB_TIMED_WAIT equ 10
1196	hidnplayr	33
1514	hidnplayr	34	; Socket Flags
		35	TF_ACKNOW equ 1 shl 0 ; ack peer immediately
		36	TF_DELACK equ 1 shl 1 ; ack, but try to delay it
		37	TF_NODELAY equ 1 shl 2 ; don't delay packets to coalesce
		38	TF_NOOPT equ 1 shl 3 ; don't use tcp options
		39	TF_SENTFIN equ 1 shl 4 ; have sent FIN
		40	TF_REQ_SCALE equ 1 shl 5 ; have/will request window scaling
		41	TF_RCVD_SCALE equ 1 shl 6 ; other side has requested scaling
		42	TF_REQ_TSTMP equ 1 shl 7 ; have/will request timestamps
		43	TF_RCVD_TSTMP equ 1 shl 8 ; a timestamp was received in SYN
		44	TF_SACK_PERMIT equ 1 shl 9 ; other side said I could SACK
1249	hidnplayr	45
1514	hidnplayr	46	; Segment flags
		47	TH_FIN equ 1 shl 0
		48	TH_SYN equ 1 shl 1
		49	TH_RST equ 1 shl 2
		50	TH_PUSH equ 1 shl 3
		51	TH_ACK equ 1 shl 4
		52	TH_URG equ 1 shl 5
1318	hidnplayr	53
1514	hidnplayr	54	; Segment header options
		55	TCP_OPT_EOL equ 0 ; End of option list.
		56	TCP_OPT_NOP equ 1 ; No-Operation.
		57	TCP_OPT_MAXSEG equ 2 ; Maximum Segment Size.
		58	TCP_OPT_WINDOW equ 3 ; window scale
		59	TCP_OPT_TIMESTAMP equ 8
		60
1519	hidnplayr	61	; Fundamental timer values
		62	TCP_time_MSL equ 47 ; max segment lifetime (30s)
		63	TCP_time_re_min equ 2 ; min retransmission (1,28s)
		64	TCP_time_re_max equ 100 ; max retransmission (64s)
		65	TCP_time_pers_min equ 8 ; min persist (5,12s)
		66	TCP_time_pers_max equ 94 ; max persist (60,16s)
		67	TCP_time_keep_init equ 118 ; connectione stablishment (75,52s)
		68	TCP_time_keep_idle equ 4608 ; idle time before 1st probe (2h)
		69	TCP_time_keep_interval equ 118 ; between probes when no response (75,52s)
		70	TCP_time_rtt_default equ 5 ; default Round Trip Time (3,2s)
		71
		72	; timer constants
		73	TCP_max_rxtshift equ 12 ; max retransmissions waiting for ACK
		74	TCP_max_keepcnt equ 8 ; max keepalive probes
		75
1529	hidnplayr	76	;
		77	TCP_max_winshift equ 14
		78	TCP_max_win equ 65535
1519	hidnplayr	79
1514	hidnplayr	80	struct TCP_segment
1159	hidnplayr	81	.SourcePort dw ?
		82	.DestinationPort dw ?
		83	.SequenceNumber dd ?
		84	.AckNumber dd ?
1196	hidnplayr	85	.DataOffset db ? ; DataOffset[0-3 bits] and Reserved[4-7]
		86	.Flags db ? ; Reserved[0-1 bits]\|URG\|ACK\|PSH\|RST\|SYN\|FIN
1159	hidnplayr	87	.Window dw ?
		88	.Checksum dw ?
		89	.UrgentPointer dw ?
1514	hidnplayr	90	.Data: ; ..or options
1159	hidnplayr	91	ends
		92
1196	hidnplayr	93	align 4
		94	uglobal
1514	hidnplayr	95	TCP_segments_tx rd IP_MAX_INTERFACES
		96	TCP_segments_rx rd IP_MAX_INTERFACES
		97	TCP_bytes_rx rq IP_MAX_INTERFACES
		98	TCP_bytes_tx rq IP_MAX_INTERFACES
		99	TCP_sequence_num dd ?
1196	hidnplayr	100	endg
		101
		102
		103	;-----------------------------------------------------------------
		104	;
		105	; TCP_init
		106	;
		107	; This function resets all TCP variables
		108	;
		109	;-----------------------------------------------------------------
1529	hidnplayr	110	macro TCP_init {
1196	hidnplayr	111
		112	xor eax, eax
1514	hidnplayr	113	mov edi, TCP_segments_tx
		114	mov ecx, (6*IP_MAX_INTERFACES)
1196	hidnplayr	115	rep stosd
		116
1529	hidnplayr	117	pseudo_random eax
		118	mov [TCP_sequence_num], eax
1196	hidnplayr	119
1529	hidnplayr	120	}
1196	hidnplayr	121
		122
1519	hidnplayr	123	;----------------------
1196	hidnplayr	124	;
1159	hidnplayr	125	;
1519	hidnplayr	126	;----------------------
1529	hidnplayr	127	macro TCP_timer_160ms {
1159	hidnplayr	128
1529	hidnplayr	129	local .loop
		130	local .exit
		131
1514	hidnplayr	132	mov eax, net_sockets
		133	.loop:
		134	mov eax, [eax + SOCKET.NextPtr]
		135	or eax, eax
1159	hidnplayr	136	jz .exit
		137
1514	hidnplayr	138	cmp [eax + SOCKET.Type], IP_PROTO_TCP
		139	jne .loop
1249	hidnplayr	140
1519	hidnplayr	141	dec [eax + TCP_SOCKET.timer_ack]
1514	hidnplayr	142	jnz .loop
1159	hidnplayr	143
1519	hidnplayr	144	DEBUGF 1,"TCP ack for socket %x expired, time to piggyback!\n", eax
1159	hidnplayr	145
1519	hidnplayr	146	push eax
1529	hidnplayr	147	call TCP_respond_socket
1514	hidnplayr	148	pop eax
1159	hidnplayr	149
1519	hidnplayr	150	jmp .loop
1159	hidnplayr	151
		152	.exit:
1519	hidnplayr	153
1529	hidnplayr	154	}
1159	hidnplayr	155
		156
1519	hidnplayr	157	;-----------------------------------------------------------------
1159	hidnplayr	158	;
		159	;
1519	hidnplayr	160	;-----------------------------------------------------------------
1529	hidnplayr	161	macro TCP_timer_640ms {
1159	hidnplayr	162
1529	hidnplayr	163	local .loop
		164	local .exit
		165
1519	hidnplayr	166	; Update TCP sequence number
		167
1514	hidnplayr	168	add [TCP_sequence_num], 64000
1159	hidnplayr	169
1519	hidnplayr	170	; scan through all the active TCP sockets, decrementing ALL timers
		171	; timers do not have the chance to wrap because of the keepalive timer will kill the socket when it expires
1159	hidnplayr	172
1519	hidnplayr	173	mov eax, net_sockets
		174	.loop:
		175	mov eax, [eax + SOCKET.NextPtr]
		176	.check_only:
		177	or eax, eax
		178	jz .exit
1159	hidnplayr	179
1519	hidnplayr	180	cmp [eax + SOCKET.Type], IP_PROTO_TCP
		181	jne .loop
1159	hidnplayr	182
1529	hidnplayr	183	inc [eax + TCP_SOCKET.t_idle]
		184	dec [eax + TCP_SOCKET.timer_retransmission]
1519	hidnplayr	185	jnz .check_more2
1254	hidnplayr	186
1519	hidnplayr	187	DEBUGF 1,"socket %x: Retransmission timer expired\n", eax
1159	hidnplayr	188
1519	hidnplayr	189	push eax
		190	call TCP_output
		191	pop eax
1159	hidnplayr	192
1519	hidnplayr	193	.check_more2:
		194	dec [eax + TCP_SOCKET.timer_keepalive]
		195	jnz .check_more3
1159	hidnplayr	196
1519	hidnplayr	197	DEBUGF 1,"socket %x: Keepalive expired\n", eax
1159	hidnplayr	198
1519	hidnplayr	199	;;; TODO: check socket state and handle accordingly
1318	hidnplayr	200
1519	hidnplayr	201	.check_more3:
		202	dec [eax + TCP_SOCKET.timer_timed_wait]
		203	jnz .check_more5
		204
		205	DEBUGF 1,"socket %x: 2MSL timer expired\n", eax
		206
		207	.check_more5:
		208	dec [eax + TCP_SOCKET.timer_persist]
		209	jnz .loop
		210
		211	DEBUGF 1,"socket %x: persist timer expired\n", eax
		212
		213	jmp .loop
		214	.exit:
1529	hidnplayr	215	}
1519	hidnplayr	216
		217
1529	hidnplayr	218
		219
		220	macro TCP_checksum IP1, IP2 {
		221
		222	;-------------
		223	; Pseudoheader
		224
		225	; protocol type
		226	mov edx, IP_PROTO_TCP
		227
		228	; source address
1530	hidnplayr	229	add dl, byte [IP1+1]
		230	adc dh, byte [IP1+0]
		231	adc dl, byte [IP1+3]
		232	adc dh, byte [IP1+2]
1529	hidnplayr	233
		234	; destination address
1530	hidnplayr	235	adc dl, byte [IP2+1]
		236	adc dh, byte [IP2+0]
		237	adc dl, byte [IP2+3]
		238	adc dh, byte [IP2+2]
1529	hidnplayr	239
		240	; size
		241	adc dl, cl
		242	adc dh, ch
		243
		244	;---------------------
		245	; Real header and data
		246
		247	push esi
		248	call checksum_1
		249	call checksum_2
		250	pop esi
		251
		252	} ; returns in dx only
		253
		254
1533	hidnplayr	255	macro TCP_sendseqinit ptr {
1529	hidnplayr	256
1533	hidnplayr	257	push edi ;;;; i dont like this static use of edi
		258	mov edi, [ptr + TCP_SOCKET.ISS]
		259	mov [ptr + TCP_SOCKET.SND_UP], edi
		260	mov [ptr + TCP_SOCKET.SND_MAX], edi
		261	mov [ptr + TCP_SOCKET.SND_NXT], edi
		262	mov [ptr + TCP_SOCKET.SND_UNA], edi
		263	pop edi
		264
		265	}
		266
		267	macro TCP_rcvseqinit ptr {
		268
		269	push edi
		270	mov edi, [ptr + TCP_SOCKET.IRS]
		271	inc edi
		272	mov [ptr + TCP_SOCKET.RCV_NXT], edi
		273	mov [ptr + TCP_SOCKET.RCV_ADV], edi
		274	pop edi
		275
		276	}
		277
		278
		279
1249	hidnplayr	280	;-----------------------------------------------------------------
		281	;
1514	hidnplayr	282	; TCP_input:
1159	hidnplayr	283	;
1514	hidnplayr	284	; IN: [esp] = ptr to buffer
		285	; [esp+4] = buffer size
		286	; ebx = ptr to device struct
		287	; ecx = segment size
		288	; edx = ptr to TCP segment
1196	hidnplayr	289	;
1514	hidnplayr	290	; esi = ipv4 source address
		291	; edi = ipv4 dest address
		292	;
1196	hidnplayr	293	; OUT: /
		294	;
		295	;-----------------------------------------------------------------
1249	hidnplayr	296	align 4
1514	hidnplayr	297	TCP_input:
1159	hidnplayr	298
1529	hidnplayr	299	DEBUGF 1,"TCP_input size=%u\n", ecx
1514	hidnplayr	300	; Offset must be greater than or equal to the size of the standard TCP header (20) and less than or equal to the TCP length.
1254	hidnplayr	301
1514	hidnplayr	302	movzx eax, [edx + TCP_segment.DataOffset]
		303	and eax, 0xf0
1529	hidnplayr	304	shr al, 2
1514	hidnplayr	305
1529	hidnplayr	306	DEBUGF 1,"headersize=%u\n", eax
1514	hidnplayr	307
		308	cmp eax, 20
		309	jl .drop
		310
		311	;-------------------------------
		312	; Now, re-calculate the checksum
		313
1529	hidnplayr	314	push eax ecx edx
		315	pushw [edx + TCP_segment.Checksum]
		316	mov [edx + TCP_segment.Checksum], 0
		317	push esi edi
1514	hidnplayr	318	mov esi, edx
1530	hidnplayr	319	TCP_checksum (esp), (esp+4)
1529	hidnplayr	320	pop esi edi ; yes, swap them (we dont need dest addr)
		321	pop cx ; previous checksum
		322	cmp cx, dx
		323	pop edx ecx esi
1514	hidnplayr	324	jnz .drop
		325
		326	DEBUGF 1,"Checksum is correct\n"
		327
1529	hidnplayr	328	sub ecx, esi ; update packet size
		329	jl .drop
1534	hidnplayr	330	DEBUGF 1,"we got %u bytes of data\n", ecx
1529	hidnplayr	331
1514	hidnplayr	332	;-----------------------------------------------------------------------------------------
		333	; Check if this packet has a timestamp option (We do it here so we can process it quickly)
		334
1529	hidnplayr	335	cmp esi, 20 + 12 ; Timestamp option is 12 bytes
1514	hidnplayr	336	jl .no_timestamp
		337	je .is_ok
		338
1529	hidnplayr	339	cmp byte [edx + TCP_segment.Data + 12], TCP_OPT_EOL ; end of option list
1514	hidnplayr	340	jne .no_timestamp
		341
		342	.is_ok:
		343	test [edx + TCP_segment.Flags], TH_SYN ; SYN flag must not be set
		344	jnz .no_timestamp
		345
		346	cmp dword [edx + TCP_segment.Data], 0x0101080a ; Timestamp header
		347	jne .no_timestamp
		348
		349	DEBUGF 1,"timestamp ok\n"
		350
1529	hidnplayr	351	; TODO: Parse the option
1514	hidnplayr	352	; TODO: Set a Bit in the TCP to tell all options are parsed
		353
		354	.no_timestamp:
		355
		356	;-------------------------------------------
		357	; Convert Big-endian values to little endian
		358
		359	ntohld [edx + TCP_segment.SequenceNumber]
		360	ntohld [edx + TCP_segment.AckNumber]
		361
		362	ntohlw [edx + TCP_segment.Window]
		363	ntohlw [edx + TCP_segment.UrgentPointer]
1529	hidnplayr	364	ntohlw [edx + TCP_segment.SourcePort]
		365	ntohlw [edx + TCP_segment.DestinationPort]
1514	hidnplayr	366
		367	;------------------------------------------------------------
		368	; Next thing to do is find the TCB (thus, the socket pointer)
		369
1274	hidnplayr	370	; IP Packet TCP Destination Port = local Port
1514	hidnplayr	371	; (IP Packet SenderAddress = Remote IP) OR (Remote IP = 0)
1318	hidnplayr	372	; (IP Packet TCP Source Port = remote Port) OR (remote Port = 0)
1159	hidnplayr	373
		374	mov ebx, net_sockets
		375
1249	hidnplayr	376	.socket_loop:
1514	hidnplayr	377	mov ebx, [ebx + SOCKET.NextPtr]
1159	hidnplayr	378	or ebx, ebx
1514	hidnplayr	379	jz .drop_with_reset
1159	hidnplayr	380
1514	hidnplayr	381	cmp [ebx + SOCKET.Type], IP_PROTO_TCP
1249	hidnplayr	382	jne .socket_loop
1159	hidnplayr	383
1514	hidnplayr	384	mov ax, [edx + TCP_segment.DestinationPort]
		385	cmp [ebx + TCP_SOCKET.LocalPort], ax
		386	jne .socket_loop
		387
		388	mov eax, [ebx + IP_SOCKET.RemoteIP]
1529	hidnplayr	389	cmp eax, edi ; sender IP
1249	hidnplayr	390	je @f
		391	test eax, eax
1514	hidnplayr	392	jnz .socket_loop
1249	hidnplayr	393	@@:
1159	hidnplayr	394
1514	hidnplayr	395	mov ax, [ebx + TCP_SOCKET.RemotePort]
		396	cmp [edx + TCP_segment.SourcePort] , ax
1274	hidnplayr	397	je .found_socket
1249	hidnplayr	398	test ax, ax
1254	hidnplayr	399	jnz .socket_loop
1274	hidnplayr	400	.found_socket:
1529	hidnplayr	401	DEBUGF 1,"Socket ptr: %x\n", ebx
1254	hidnplayr	402
1514	hidnplayr	403	; ebx now contains the pointer to the socket
1257	hidnplayr	404
1514	hidnplayr	405	;----------------------------
		406	; Check if socket isnt closed
		407
1529	hidnplayr	408	cmp [ebx + TCP_SOCKET.t_state], TCB_CLOSED
1514	hidnplayr	409	je .drop
		410
		411	;----------------
		412	; Lock the socket
		413
1529	hidnplayr	414	;; add ebx, SOCKET.lock ; TODO: figure out if we should lock now already
		415	;; call wait_mutex
		416	;; sub ebx, SOCKET.lock
1159	hidnplayr	417
1529	hidnplayr	418	DEBUGF 1,"Socket locked\n"
1159	hidnplayr	419
1529	hidnplayr	420	;----------------------------------------------------------------------------------------
		421	; unscale the window into a 32 bit value (notice that SND_SCALE must be initialised to 0)
		422
1514	hidnplayr	423	movzx eax, [edx + TCP_segment.Window]
1534	hidnplayr	424	push ecx
1529	hidnplayr	425	mov cl, [ebx + TCP_SOCKET.SND_SCALE]
1514	hidnplayr	426	shl eax, cl
1534	hidnplayr	427	pop ecx
1514	hidnplayr	428
1529	hidnplayr	429	;;;; do something with eax
1514	hidnplayr	430
		431	;-----------------------------------
		432	; Is this socket a listening socket?
		433
1533	hidnplayr	434	test [ebx + SOCKET.options], SO_ACCEPTCON
1529	hidnplayr	435	; jnz .listening_socket ;;;;; TODO
1514	hidnplayr	436
1529	hidnplayr	437	;-------------------------------------
		438	; Reset idle timer and keepalive timer
1514	hidnplayr	439
1529	hidnplayr	440	mov [ebx + TCP_SOCKET.t_idle], 0
		441	mov [ebx + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval
1514	hidnplayr	442
1529	hidnplayr	443	;--------------------
		444	; Process TCP options
1514	hidnplayr	445
1529	hidnplayr	446	cmp esi, 20 ; esi is headersize
		447	je .no_options
1514	hidnplayr	448
1529	hidnplayr	449	DEBUGF 1,"Segment has options\n"
1514	hidnplayr	450
1530	hidnplayr	451	cmp [ebx + TCP_SOCKET.t_state], TCB_LISTEN ; no options when in listen state
1529	hidnplayr	452	jz .no_options
1514	hidnplayr	453
1529	hidnplayr	454	lea edi, [edx + TCP_segment.Data]
		455	lea eax, [edx + esi]
1514	hidnplayr	456
1529	hidnplayr	457	.opt_loop:
		458	cmp edi, eax
		459	jge .no_options
1514	hidnplayr	460
1529	hidnplayr	461	cmp byte [edi], TCP_OPT_EOL ; end of option list?
		462	jz .no_options
1514	hidnplayr	463
1529	hidnplayr	464	cmp byte [edi], TCP_OPT_NOP ; nop ?
		465	jz .opt_nop
1514	hidnplayr	466
1529	hidnplayr	467	cmp byte [edi], TCP_OPT_MAXSEG
		468	je .opt_maxseg
1514	hidnplayr	469
1529	hidnplayr	470	cmp byte [edi], TCP_OPT_WINDOW
		471	je .opt_window
1514	hidnplayr	472
1529	hidnplayr	473	cmp byte [edi], TCP_OPT_TIMESTAMP
		474	je .opt_timestamp
1514	hidnplayr	475
1529	hidnplayr	476	jmp .no_options ; If we reach here, some unknown options were received, skip them all!
1514	hidnplayr	477
1529	hidnplayr	478	.opt_nop:
		479	inc edi
		480	jmp .opt_loop
1514	hidnplayr	481
1529	hidnplayr	482	.opt_maxseg:
		483	cmp byte [edi+1], 4
		484	jne .no_options ; error occured, ignore all options!
1514	hidnplayr	485
1529	hidnplayr	486	test [edx + TCP_segment.Flags], TH_SYN
		487	jz @f
		488
1530	hidnplayr	489	movzx eax, word[edi+2]
		490	rol ax, 8
1533	hidnplayr	491	DEBUGF 1,"Maxseg: %u\n", ax
1529	hidnplayr	492
1530	hidnplayr	493	mov [ebx + TCP_SOCKET.t_maxseg], eax
		494
1529	hidnplayr	495	@@:
		496	add edi, 4
		497	jmp .opt_loop
		498
		499
		500	.opt_window:
		501	cmp byte [edi+1], 3
		502	jne .no_options
		503
		504	test [edx + TCP_segment.Flags], TH_SYN
		505	jz @f
		506
1533	hidnplayr	507	DEBUGF 1,"Got window option\n"
1529	hidnplayr	508
		509	;;;;;
		510	@@:
		511	add edi, 3
		512	jmp .opt_loop
		513
		514
		515	.opt_timestamp:
		516	cmp byte [edi+1], 10
		517	jne .no_options
		518
1533	hidnplayr	519	DEBUGF 1,"Got timestamp option\n"
1529	hidnplayr	520
		521	;;;;;
		522
		523	add edi, 10
		524	jmp .opt_loop
		525
		526	.no_options:
		527
1514	hidnplayr	528	;-----------------------------------------------------------------------
		529	; Time to do some header prediction (Original Principle by Van Jacobson)
		530
		531	; There are two common cases for an uni-directional data transfer.
		532	;
		533	; General rule: the packets has no control flags, is in-sequence,
		534	; window width didnt change and we're not retransmitting.
		535	;
		536	; Second rules:
		537	; - If the length is 0 and the ACK moved forward, we're the sender side of the transfer.
		538	; In this case we'll free the ACK'ed data and notify higher levels that we have free space in buffer
		539	;
		540	; - If the length is not 0 and the ACK didn't move, we're the receiver side of the transfer.
		541	; If the packets are in order (data queue is empty), add the data to the socket buffer and request a delayed ACK
		542
1529	hidnplayr	543	cmp [ebx + TCP_SOCKET.t_state], TCB_ESTABLISHED
1514	hidnplayr	544	jnz .not_uni_xfer
		545
1529	hidnplayr	546	test [edx + TCP_segment.Flags], TH_SYN + TH_FIN + TH_RST + TH_URG
1514	hidnplayr	547	jnz .not_uni_xfer
		548
1529	hidnplayr	549	test [edx + TCP_segment.Flags], TH_ACK
1514	hidnplayr	550	jz .not_uni_xfer
		551
		552	mov eax, [edx + TCP_segment.SequenceNumber]
		553	cmp eax, [ebx + TCP_SOCKET.RCV_NXT]
		554	jne .not_uni_xfer
		555
1536	hidnplayr	556	movzx eax, [edx + TCP_segment.Window] ;;;;; (should use pre-calculated value instead: todo: figure out where to store it)
		557	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		558	jne .not_uni_xfer
1514	hidnplayr	559
		560	mov eax, [ebx + TCP_SOCKET.SND_NXT]
		561	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		562	jne .not_uni_xfer
		563
		564	;---------------------------------------
		565	; check if we are sender in the uni-xfer
		566
		567	; If the following 4 conditions are all true, this segment is a pure ACK.
		568	;
1529	hidnplayr	569	; - The segment contains no data.
		570	test ecx, ecx
1514	hidnplayr	571	jnz .not_sender
1274	hidnplayr	572
1529	hidnplayr	573	; - The congestion window is greater than or equal to the current send window.
1514	hidnplayr	574	; This test is true only if the window is fully open, that is, the connection is not in the middle of slow start or congestion avoidance.
		575	mov eax, [ebx + TCP_SOCKET.SND_CWND]
		576	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		577	jl .not_uni_xfer
1318	hidnplayr	578
1529	hidnplayr	579	; - The acknowledgment field in the segment is less than or equal to the maximum sequence number sent.
1534	hidnplayr	580	mov eax, [edx + TCP_segment.AckNumber]
		581	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
1529	hidnplayr	582	jg .not_uni_xfer
		583
		584	; - The acknowledgment field in the segment is greater than the largest unacknowledged sequence number.
1534	hidnplayr	585	sub eax, [ebx + TCP_SOCKET.SND_UNA]
1529	hidnplayr	586	jle .not_uni_xfer
		587
1514	hidnplayr	588	DEBUGF 1,"Header prediction: we are sender\n"
1274	hidnplayr	589
1514	hidnplayr	590	;---------------------------------
		591	; Packet is a pure ACK, process it
1274	hidnplayr	592
1514	hidnplayr	593	; Update RTT estimators
1159	hidnplayr	594
1514	hidnplayr	595	; Delete acknowledged bytes from send buffer
1536	hidnplayr	596	mov ecx, eax
1533	hidnplayr	597	lea eax, [ebx + STREAM_SOCKET.snd]
1529	hidnplayr	598	call SOCKET_ring_free
		599
1536	hidnplayr	600	; update window pointers
		601	mov eax, [edx + TCP_segment.AckNumber]
		602	dec eax
		603	mov [ebx + TCP_SOCKET.SND_WL1], eax
		604
1514	hidnplayr	605	; Stop retransmit timer
1519	hidnplayr	606	mov [ebx + TCP_SOCKET.timer_ack], 0
1159	hidnplayr	607
1514	hidnplayr	608	; Awaken waiting processes
1519	hidnplayr	609	mov eax, ebx
		610	call SOCKET_notify_owner
1318	hidnplayr	611
1536	hidnplayr	612	;; Generate more output
		613	;; mov eax, ebx
		614	;; call TCP_output
		615	;;
		616	;; jmp .drop
		617	jmp .step6
1254	hidnplayr	618
1514	hidnplayr	619	;-------------------------------------------------
		620	; maybe we are the receiver in the uni-xfer then..
		621
		622	.not_sender:
1529	hidnplayr	623	; - The amount of data in the segment is greater than 0 (data count is in ecx)
1514	hidnplayr	624
1529	hidnplayr	625	; - The acknowledgment field equals the largest unacknowledged sequence number. This means no data is acknowledged by this segment.
1514	hidnplayr	626	mov eax, [edx + TCP_segment.AckNumber]
		627	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
		628	jne .not_uni_xfer
		629
1529	hidnplayr	630	; - The reassembly list of out-of-order segments for the connection is empty (seg_next equals tp). ;;;;;;;
1514	hidnplayr	631
		632	jnz .not_uni_xfer
		633
		634	;-------------------------------------
		635	; Complete processing of received data
		636
		637	DEBUGF 1,"header prediction: we are receiver\nreceiving %u bytes of data\n", ecx
		638
1529	hidnplayr	639	add esi, edx
1533	hidnplayr	640	lea eax, [ebx + STREAM_SOCKET.rcv]
		641	call SOCKET_ring_write ; Add the data to the socket buffer
1514	hidnplayr	642
1533	hidnplayr	643	mov eax, ebx
		644	call SOCKET_notify_owner
		645
1529	hidnplayr	646	add [ebx + TCP_SOCKET.RCV_NXT], ecx ; Update sequence number with number of bytes we have copied
		647	or [ebx + TCP_SOCKET.t_flags], TF_DELACK ; Set delayed ack flag
1514	hidnplayr	648
		649	jmp .drop
		650
		651	;----------------------------------------------------
1529	hidnplayr	652	; Header prediction failed, doing it the slow way.. ;;;;; current implementation of header prediction destroys some regs (ecx) !!
1514	hidnplayr	653
		654	.not_uni_xfer:
		655
1533	hidnplayr	656	DEBUGF 1,"Header prediction failed\n" ; time to do it the "slow" way :)
1514	hidnplayr	657
		658	;------------------------------
		659	; Calculate receive window size
		660
		661	;;;;
		662
1529	hidnplayr	663	cmp [ebx + TCP_SOCKET.t_state], TCB_LISTEN
1514	hidnplayr	664	je .LISTEN
		665
1529	hidnplayr	666	cmp [ebx + TCP_SOCKET.t_state], TCB_SYN_SENT
1514	hidnplayr	667	je .SYN_SENT
		668
		669	;--------------------------------------------
		670	; Protection Against Wrapped Sequence Numbers
		671
1533	hidnplayr	672	; First, check if timestamp is present
1514	hidnplayr	673
		674	;;;; TODO
		675
		676	; Then, check if at least some bytes of data are within window
		677
		678	;;;; TODO
		679
		680	jmp .trim_then_step6
		681
1529	hidnplayr	682	;-------------
		683	; Passive Open
		684
1249	hidnplayr	685	align 4
1514	hidnplayr	686	.LISTEN:
1196	hidnplayr	687
1514	hidnplayr	688	DEBUGF 1,"TCP state: listen\n"
1159	hidnplayr	689
1514	hidnplayr	690	test [edx + TCP_segment.Flags], TH_RST
		691	jnz .drop
1159	hidnplayr	692
1514	hidnplayr	693	test [edx + TCP_segment.Flags], TH_ACK
		694	jnz .drop_with_reset
1159	hidnplayr	695
1514	hidnplayr	696	test [edx + TCP_segment.Flags], TH_SYN
		697	jz .drop
1159	hidnplayr	698
1533	hidnplayr	699	cmp esi, 0xffffff ; destination ip = 255.255.255.255 ?
		700	jz .drop
		701
1514	hidnplayr	702	; TODO: check if it's a broadcast or multicast, and drop if so
1159	hidnplayr	703
1529	hidnplayr	704	call SOCKET_fork
		705	jz .drop ; if we could not open a new connection, drop segment (;;;; should we send RST too?)
1514	hidnplayr	706
1529	hidnplayr	707	;-----------------------
		708	; Fill in some variables
1514	hidnplayr	709
1529	hidnplayr	710	add [TCP_sequence_num], 64000
1514	hidnplayr	711
1529	hidnplayr	712	push [edx + TCP_segment.SourcePort]
		713	pop [eax + TCP_SOCKET.RemotePort]
1514	hidnplayr	714
1529	hidnplayr	715	push [edx + TCP_segment.SequenceNumber]
		716	pop [eax + TCP_SOCKET.IRS]
1159	hidnplayr	717
1529	hidnplayr	718	push [eax + TCP_SOCKET.ISS]
		719	pop [eax + TCP_SOCKET.SND_NXT]
1159	hidnplayr	720
1529	hidnplayr	721	mov [eax + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		722	mov [eax + TCP_SOCKET.t_flags], TF_ACKNOW
		723	mov [eax + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval
1159	hidnplayr	724
1529	hidnplayr	725	mov ebx, eax
1514	hidnplayr	726	jmp .trim_then_step6
1159	hidnplayr	727
1254	hidnplayr	728
1529	hidnplayr	729	;------------
		730	; Active Open
1159	hidnplayr	731
1514	hidnplayr	732	align 4
		733	.SYN_SENT:
1281	hidnplayr	734
1514	hidnplayr	735	DEBUGF 1,"TCP state: syn_sent\n"
1159	hidnplayr	736
1514	hidnplayr	737	test [edx + TCP_segment.Flags], TH_ACK
		738	jz @f
1281	hidnplayr	739
1514	hidnplayr	740	mov eax, [edx + TCP_segment.AckNumber]
		741	cmp eax, [ebx + TCP_SOCKET.ISS]
		742	jle .drop_with_reset
1281	hidnplayr	743
1529	hidnplayr	744	; mov eax, [edx + TCP_segment.AckNumber]
1533	hidnplayr	745	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		746	jg .drop_with_reset
1514	hidnplayr	747	@@:
1281	hidnplayr	748
1514	hidnplayr	749	test [edx + TCP_segment.Flags], TH_RST
		750	jz @f
1281	hidnplayr	751
1514	hidnplayr	752	test [edx + TCP_segment.Flags], TH_ACK
		753	jz .drop
1281	hidnplayr	754
1514	hidnplayr	755	;tp = tcp_drop(tp, ECONNREFUSED)
1159	hidnplayr	756
1514	hidnplayr	757	jmp .drop
		758	@@:
1159	hidnplayr	759
1514	hidnplayr	760	test [edx + TCP_segment.Flags], TH_SYN
		761	jz .drop
1318	hidnplayr	762
1529	hidnplayr	763	; at this point, segment seems to be valid
		764
1514	hidnplayr	765	test [edx + TCP_segment.Flags], TH_ACK
1529	hidnplayr	766	jz .no_syn_ack
1514	hidnplayr	767
1529	hidnplayr	768	; now, process received SYN in response to an active open
		769
1514	hidnplayr	770	mov eax, [edx + TCP_segment.AckNumber]
		771	mov [ebx + TCP_SOCKET.SND_UNA], eax
		772	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		773	jle @f
		774	mov [ebx + TCP_SOCKET.SND_NXT], eax
1529	hidnplayr	775	@@:
1514	hidnplayr	776
1529	hidnplayr	777	.no_syn_ack:
1514	hidnplayr	778
1529	hidnplayr	779	mov [ebx + TCP_SOCKET.timer_retransmission], 0 ; disable retransmission
1514	hidnplayr	780
1529	hidnplayr	781	push [edx + TCP_segment.SequenceNumber]
		782	pop [ebx + TCP_SOCKET.IRS]
		783
1533	hidnplayr	784	TCP_rcvseqinit ebx
1529	hidnplayr	785
		786	mov [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
		787
		788	mov eax, [ebx + TCP_SOCKET.SND_UNA]
		789	cmp eax, [ebx + TCP_SOCKET.ISS]
		790	jle .simultaneous_open
		791
		792	test [edx + TCP_segment.Flags], TH_ACK
		793	jz .simultaneous_open
		794
		795	DEBUGF 1,"TCP: active open\n"
		796
		797	; TODO: update stats
1533	hidnplayr	798	; TODO: set general socket state to connected
1514	hidnplayr	799
		800	mov [ebx + TCP_SOCKET.t_state], TCB_ESTABLISHED
		801
		802	; TODO: check if we should scale the connection (567-572)
		803	; TODO: update RTT estimators
		804
1529	hidnplayr	805	jmp .trimthenstep6
1514	hidnplayr	806
1529	hidnplayr	807	.simultaneous_open:
1514	hidnplayr	808
1529	hidnplayr	809	DEBUGF 1,"TCP: simultaneous open\n"
1514	hidnplayr	810	; We have received a syn but no ACK, so we are having a simultaneous open..
		811	mov [ebx + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		812
		813	;-------------------------------------
		814	; Common processing for receipt of SYN
		815
		816	.trimthenstep6:
		817
		818	inc [edx + TCP_segment.SequenceNumber]
		819
		820	cmp cx, [ebx + TCP_SOCKET.RCV_WND]
		821	jle @f
		822
		823	movzx eax, cx
		824	sub ax, [ebx + TCP_SOCKET.RCV_WND]
		825	; TODO: 592
		826	mov cx, [ebx + TCP_SOCKET.RCV_WND]
		827	; TODO...
		828	@@:
		829	;;;;;
1529	hidnplayr	830	jmp .step6
1514	hidnplayr	831
		832
		833
		834
		835
1529	hidnplayr	836	.trim_then_step6:
1159	hidnplayr	837
1514	hidnplayr	838	;----------------------------
		839	; trim any data not in window
1159	hidnplayr	840
1533	hidnplayr	841	DEBUGF 1,"Trimming window\n"
		842
1514	hidnplayr	843	mov eax, [ebx + TCP_SOCKET.RCV_NXT]
		844	sub eax, [edx + TCP_segment.SequenceNumber]
1318	hidnplayr	845
1514	hidnplayr	846	test eax, eax
1533	hidnplayr	847	jz .no_duplicate
1274	hidnplayr	848
1514	hidnplayr	849	test [edx + TCP_segment.Flags], TH_SYN
		850	jz .no_drop
		851
		852	and [edx + TCP_segment.Flags], not (TH_SYN)
		853	inc [edx + TCP_segment.SequenceNumber]
		854
		855	cmp [edx + TCP_segment.UrgentPointer], 1
		856	jl @f
		857
		858	dec [edx + TCP_segment.UrgentPointer]
		859
		860	jmp .no_drop
		861	@@:
		862
		863	and [edx + TCP_segment.Flags], not (TH_URG)
		864	dec eax
1533	hidnplayr	865	jz .no_duplicate
1514	hidnplayr	866	.no_drop:
		867
1533	hidnplayr	868	DEBUGF 1,"Going to drop %u out of %u bytes\n", eax, ecx
1529	hidnplayr	869
1514	hidnplayr	870	; eax holds number of bytes to drop
		871
		872	;----------------------------------
		873	; Check for entire duplicate packet
		874
		875	cmp eax, ecx
		876	jge .duplicate
		877
		878	;;; TODO: figure 28.30
		879
		880	;------------------------
		881	; Check for duplicate FIN
		882
		883	test [edx + TCP_segment.Flags], TH_FIN
		884	jz @f
		885	inc ecx
		886	cmp eax, ecx
		887	dec ecx
		888	jne @f
		889
		890	mov eax, ecx
		891	and [edx + TCP_segment.Flags], not TH_FIN
1529	hidnplayr	892	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1514	hidnplayr	893	jmp .no_duplicate
		894	@@:
		895
		896	; Handle the case when a bound socket connects to itself
		897	; Allow packets with a SYN and an ACKto continue with the processing
		898
		899	;-------------------------------------
		900	; Generate duplicate ACK if nescessary
		901
		902	; This code also handles simultaneous half-open or self-connects
		903
		904	test eax, eax
		905	jnz .drop_after_ack
		906
		907	cmp [edx + TCP_segment.Flags], TH_ACK
		908	jz .drop_after_ack
		909
		910	.duplicate:
		911
1533	hidnplayr	912	DEBUGF 1,"Duplicate received\n"
1529	hidnplayr	913
1514	hidnplayr	914	;----------------------------------------
		915	; Update statistics for duplicate packets
		916
		917	;;; TODO
		918
1529	hidnplayr	919	jmp .drop ;;; DROP the packet ??
1514	hidnplayr	920
		921	.no_duplicate:
		922
		923	;-----------------------------------------------
		924	; Remove duplicate data and update urgent offset
		925
		926	add [edx + TCP_segment.SequenceNumber], eax
		927
		928	;;; TODO
		929
		930	sub [edx + TCP_segment.UrgentPointer], ax
		931	jg @f
		932
		933	and [edx + TCP_segment.Flags], not (TH_URG)
		934	mov [edx + TCP_segment.UrgentPointer], 0
		935	@@:
		936
		937	;--------------------------------------------------
		938	; Handle data that arrives after process terminates
		939
		940	cmp [ebx + SOCKET.PID], 0
1533	hidnplayr	941	jg @f
1514	hidnplayr	942
		943	cmp [ebx + TCP_SOCKET.t_state], TCB_CLOSE_WAIT
		944	jle @f
		945
		946	test ecx, ecx
		947	jz @f
		948
		949	;;; Close the socket
		950	;;; update stats
		951
		952	jmp .drop_with_reset
		953	@@:
		954
		955	;----------------------------------------
		956	; Remove data beyond right edge of window
		957
		958	mov eax, [edx + TCP_segment.SequenceNumber]
		959	add eax, ecx
		960	sub eax, [ebx + TCP_SOCKET.RCV_NXT]
		961	sub ax, [ebx + TCP_SOCKET.RCV_WND]
		962
		963	; eax now holds the number of bytes to drop
		964
		965	jle .no_excess_data
		966
		967	;;; TODO: update stats
		968
		969	cmp eax, ecx
		970	jl .dont_drop_all
		971
		972	;;; TODO 700-736
		973
		974	.dont_drop_all:
		975
		976	.no_excess_data:
		977
		978	;-----------------
		979	; Record timestamp
		980
		981	;;; TODO 737-746
		982
		983	;------------------
		984	; Process RST flags
		985
		986	test [edx + TCP_segment.Flags], TH_RST
		987	jz .rst_skip
		988
1529	hidnplayr	989	DEBUGF 1,"Got an RST flag"
		990
1514	hidnplayr	991	mov eax, [ebx + TCP_SOCKET.t_state]
		992	shl eax, 2
		993	jmp dword [eax + .rst_sw_list]
		994
		995	.rst_sw_list:
		996	dd .rst_skip ;TCB_CLOSED
		997	dd .rst_skip ;TCB_LISTEN
		998	dd .rst_skip ;TCB_SYN_SENT
		999	dd .econnrefused ;TCB_SYN_RECEIVED
		1000	dd .econnreset ;TCB_ESTABLISHED
		1001	dd .econnreset ;TCB_CLOSE_WAIT
		1002	dd .econnreset ;TCB_FIN_WAIT_1
		1003	dd .rst_close ;TCB_CLOSING
		1004	dd .rst_close ;TCB_LAST_ACK
		1005	dd .econnreset ;TCB_FIN_WAIT_2
		1006	dd .rst_close ;TCB_TIMED_WAIT
		1007
		1008	.econnrefused:
		1009
1529	hidnplayr	1010	DEBUGF 1,"Connection refused"
		1011
1514	hidnplayr	1012	;;; TODO: debug info
		1013
		1014	jmp .close
		1015
		1016	.econnreset:
		1017
1529	hidnplayr	1018	DEBUGF 1,"Connection reset"
		1019
1514	hidnplayr	1020	;;; TODO: debug info
1529	hidnplayr	1021	.close:
1514	hidnplayr	1022
1529	hidnplayr	1023	DEBUGF 1,"Closing connection"
		1024
1514	hidnplayr	1025	;;; update stats
		1026
		1027	.rst_close:
		1028
1534	hidnplayr	1029	DEBUGF 1,"Closing with reset\n"
1529	hidnplayr	1030
1514	hidnplayr	1031	;;; Close the socket
		1032	jmp .drop
		1033
		1034	.rst_skip:
		1035
		1036	;--------------------------------------
		1037	; handle SYN-full and ACK-less segments
		1038
		1039	test [edx + TCP_segment.Flags], TH_SYN
		1040	jz @f
		1041
		1042	;;; tcp_drop ( ECONNRESET)
		1043	jmp .drop_with_reset
		1044
		1045	test [edx + TCP_segment.Flags], TH_ACK
		1046	jz .drop
1534	hidnplayr	1047	@@:
1514	hidnplayr	1048	;----------------
		1049	; Process the ACK
		1050
		1051	cmp [ebx + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		1052	jg .ack_dup
		1053	jl .ack_nodup
		1054
1534	hidnplayr	1055	DEBUGF 1,"TCP state = syn received\n"
1533	hidnplayr	1056
1514	hidnplayr	1057	;;;;;
		1058
1536	hidnplayr	1059	.ack_nodup:
1514	hidnplayr	1060
1536	hidnplayr	1061	DEBUGF 1,"New ACK\n"
1533	hidnplayr	1062
1514	hidnplayr	1063
		1064
1536	hidnplayr	1065	.ack_dup:
1514	hidnplayr	1066
1536	hidnplayr	1067	;;;;
1533	hidnplayr	1068
1514	hidnplayr	1069	;-------------------------------------------------
1519	hidnplayr	1070	; If the congestion window was inflated to account
1514	hidnplayr	1071	; for the other side's cached packets, retrace it
		1072
		1073	;;;; 888 - 902
		1074
		1075
		1076	;------------------------------------------
		1077	; RTT measurements and retransmission timer
		1078
		1079	;;;;; 903 - 926
		1080
1519	hidnplayr	1081	mov [ebx + TCP_SOCKET.timer_retransmission], 0
1514	hidnplayr	1082
1519	hidnplayr	1083	mov eax, [ebx + TCP_SOCKET.SND_MAX]
		1084	cmp eax, [edx + TCP_segment.AckNumber]
		1085	je .all_outstanding
		1086	mov [ebx + TCP_SOCKET.timer_retransmission], 120 ;;;; TODO: correct this value
		1087	.all_outstanding:
		1088
1514	hidnplayr	1089	;-------------------------------------------
		1090	; Open congestion window in response to ACKs
		1091
		1092	;;;;
		1093
		1094
		1095	;------------------------------------------
		1096	; Remove acknowledged data from send buffer
		1097
1536	hidnplayr	1098	pusha
		1099	; Delete acknowledged bytes from send buffer
		1100	mov ecx, [edx + TCP_segment.AckNumber]
		1101	sub ecx, [ebx + TCP_SOCKET.SND_UNA]
1533	hidnplayr	1102	lea eax, [ebx + STREAM_SOCKET.snd]
1536	hidnplayr	1103	call SOCKET_ring_free
		1104	popa
1514	hidnplayr	1105
1536	hidnplayr	1106
		1107	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; code missing (943?)
		1108
		1109	mov eax, [edx + TCP_segment.AckNumber]
		1110	mov [ebx + TCP_SOCKET.SND_UNA], eax
		1111
		1112	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		1113	jl @f
		1114	mov [ebx + TCP_SOCKET.SND_NXT], eax
		1115	@@:
		1116
		1117	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
		1118
1514	hidnplayr	1119	;---------------------------------------
		1120	; Wake up process waiting on send buffer
		1121
1529	hidnplayr	1122	mov eax, ebx
		1123	call SOCKET_notify_owner
1514	hidnplayr	1124
		1125	mov eax, [ebx + TCP_SOCKET.t_state]
		1126	shl eax, 2
		1127	jmp dword [eax + .ACK_sw_list]
		1128
		1129	.ACK_sw_list:
		1130	dd .step6 ;TCB_CLOSED
		1131	dd .step6 ;TCB_LISTEN
		1132	dd .step6 ;TCB_SYN_SENT
		1133	dd .step6 ;TCB_SYN_RECEIVED
		1134	dd .step6 ;TCB_ESTABLISHED
		1135	dd .step6 ;TCB_CLOSE_WAIT
		1136	dd ._963 ;TCB_FIN_WAIT_1
		1137	dd ._958 ;TCB_CLOSING
		1138	dd ._999 ;TCB_LAST_ACK
		1139	dd .step6 ;TCB_FIN_WAIT_2
		1140	dd ._1010 ;TCB_TIMED_WAIT
		1141
		1142
1536	hidnplayr	1143	._963:
1514	hidnplayr	1144
		1145
		1146	jmp .step6
		1147
		1148
1536	hidnplayr	1149	._958:
1514	hidnplayr	1150
		1151	jmp .step6
		1152
1536	hidnplayr	1153	._999:
1514	hidnplayr	1154
		1155	jmp .step6
		1156
		1157
1536	hidnplayr	1158	._1010:
1514	hidnplayr	1159
		1160	jmp .step6
		1161
		1162
1536	hidnplayr	1163	.step6:
1514	hidnplayr	1164
		1165	DEBUGF 1,"step 6\n"
		1166
1536	hidnplayr	1167	;----------------------------------------------
		1168	; check if we need to update window information
1514	hidnplayr	1169
		1170	test [edx + TCP_segment.Flags], TH_ACK
		1171	jz .no_window_update
		1172
		1173	mov eax, [ebx + TCP_SOCKET.SND_WL1]
		1174	cmp eax, [edx + TCP_segment.SequenceNumber]
1536	hidnplayr	1175	jl .update_window
		1176	jg @f
1514	hidnplayr	1177
		1178	mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1179	cmp eax, [edx + TCP_segment.AckNumber]
1536	hidnplayr	1180	jl .update_window
		1181	jg .no_window_update
		1182	@@:
1514	hidnplayr	1183
1536	hidnplayr	1184	mov eax, [ebx + TCP_SOCKET.SND_WL2] ;;;;
		1185	cmp eax, [edx + TCP_segment.AckNumber]
		1186	jne .no_window_update
		1187
		1188	movzx eax, [edx + TCP_segment.Window]
1514	hidnplayr	1189	cmp eax, [ebx + TCP_SOCKET.SND_WND]
1536	hidnplayr	1190	jle .no_window_update
1514	hidnplayr	1191
1536	hidnplayr	1192	.update_window:
1514	hidnplayr	1193
1536	hidnplayr	1194	DEBUGF 1,"Updating window\n"
1514	hidnplayr	1195
1536	hidnplayr	1196	;----------------------------------
		1197	; Keep track of pure window updates
		1198
		1199	; test ecx, ecx
		1200	; jz @f
		1201	;
		1202	; mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1203	; cmp eax, [edx + TCP_segment.AckNumber]
		1204	; jne @f
		1205	;
		1206	; ;; mov eax, tiwin
		1207	; cmp eax, [ebx + TCP_SOCKET.SND_WND]
		1208	; jle @f
		1209	;
		1210	; ;;; update stats
		1211	;
		1212	; @@:
		1213
		1214	movzx eax, [edx + TCP_segment.Window] ;;; FIXME: use pre-calculated value instead!
1514	hidnplayr	1215	cmp eax, [ebx + TCP_SOCKET.max_sndwnd]
		1216	jle @f
		1217	mov [ebx + TCP_SOCKET.max_sndwnd], eax
		1218	@@:
		1219	mov [ebx + TCP_SOCKET.SND_WND], eax
		1220
1536	hidnplayr	1221	push [edx + TCP_segment.SequenceNumber]
		1222	pop [ebx + TCP_SOCKET.SND_WL1]
1514	hidnplayr	1223
1536	hidnplayr	1224	push [edx + TCP_segment.AckNumber]
		1225	pop [ebx + TCP_SOCKET.SND_WL2]
1514	hidnplayr	1226
		1227	;;; needoutput = 1
		1228
		1229	.no_window_update:
		1230
		1231	;-----------------
		1232	; process URG flag
		1233
		1234	test [edx + TCP_segment.Flags], TH_URG
		1235	jz .not_urgent
		1236
		1237	cmp [edx + TCP_segment.UrgentPointer], 0
		1238	jz .not_urgent
		1239
		1240	cmp [ebx + TCP_SOCKET.t_state], TCB_TIMED_WAIT
		1241	je .not_urgent
		1242
		1243	; Ignore bogus urgent offsets
		1244
		1245	;;; 1040-1050
		1246
		1247	movzx eax, [edx + TCP_segment.UrgentPointer]
1533	hidnplayr	1248	add eax, [ebx + STREAM_SOCKET.rcv + RING_BUFFER.size]
1514	hidnplayr	1249	cmp eax, SOCKET_MAXDATA
		1250	jle .not_urgent
		1251
		1252	mov [edx + TCP_segment.UrgentPointer], 0
		1253	and [edx + TCP_segment.Flags], not (TH_URG)
		1254	jmp .do_data
		1255
		1256	.not_urgent:
		1257
		1258	;--------------------------------------
		1259	; processing of received urgent pointer
		1260
1529	hidnplayr	1261	;;; TODO (1051-1093)
1514	hidnplayr	1262
1529	hidnplayr	1263	;--------------------------------
		1264	; process the data in the segment
1514	hidnplayr	1265
1529	hidnplayr	1266	.do_data:
1514	hidnplayr	1267
1534	hidnplayr	1268	DEBUGF 1,"TCP: do data (%u)\n", ecx
1514	hidnplayr	1269
		1270	test [edx + TCP_segment.Flags], TH_FIN
1529	hidnplayr	1271	jnz .process_fin
1514	hidnplayr	1272
1533	hidnplayr	1273	cmp [ebx + TCP_SOCKET.t_state], TCB_FIN_WAIT_1
1514	hidnplayr	1274	jge .dont_do_data
		1275
1533	hidnplayr	1276	test ecx, ecx
		1277	jz .final_processing
		1278
1514	hidnplayr	1279	DEBUGF 1,"Processing data in segment\n"
		1280
1533	hidnplayr	1281	;; TODO: check if data is in sequence !
1514	hidnplayr	1282
1533	hidnplayr	1283	movzx eax, [edx + TCP_segment.DataOffset] ;;; todo: remember this in.. edi ?
		1284	and eax, 0xf0
		1285	shr al, 2
		1286
		1287	lea esi, [edx + eax]
		1288
		1289	or [ebx + TCP_SOCKET.t_flags], TF_DELACK
		1290	add [ebx + TCP_SOCKET.RCV_NXT], ecx ;;; right ?
		1291
		1292	lea eax, [ebx + STREAM_SOCKET.rcv]
		1293	call SOCKET_ring_write
		1294
		1295	mov eax, ebx
		1296	call SOCKET_notify_owner
		1297
1514	hidnplayr	1298	jmp .final_processing
		1299
		1300
		1301	.dont_do_data:
		1302
		1303	;---------------
		1304	; FIN processing
		1305
		1306	.process_fin:
		1307
		1308	DEBUGF 1,"Processing FIN\n"
		1309
		1310	mov eax, [ebx + TCP_SOCKET.t_state]
		1311	shl eax, 2
		1312	jmp dword [eax + .FIN_sw_list]
		1313
		1314	.FIN_sw_list:
		1315	dd .no_fin ;TCB_CLOSED
		1316	dd .no_fin ;TCB_LISTEN
		1317	dd .no_fin ;TCB_SYN_SENT
1533	hidnplayr	1318	dd .fin_syn_est ;TCB_SYN_RECEIVED
		1319	dd .fin_syn_est ;TCB_ESTABLISHED
1514	hidnplayr	1320	dd .no_fin ;TCB_CLOSE_WAIT
1533	hidnplayr	1321	dd .fin_wait1 ;TCB_FIN_WAIT_1
1514	hidnplayr	1322	dd .no_fin ;TCB_CLOSING
		1323	dd .no_fin ;TCB_LAST_ACK
1533	hidnplayr	1324	dd .fin_wait2 ;TCB_FIN_WAIT_2
		1325	dd .fin_timed ;TCB_TIMED_WAIT
1514	hidnplayr	1326
		1327
		1328
1533	hidnplayr	1329	.fin_syn_est:
1514	hidnplayr	1330
1533	hidnplayr	1331	jmp .final_processing
1514	hidnplayr	1332
1533	hidnplayr	1333	.fin_wait1:
1514	hidnplayr	1334
1533	hidnplayr	1335	jmp .final_processing
1514	hidnplayr	1336
1533	hidnplayr	1337	.fin_wait2:
1514	hidnplayr	1338
1533	hidnplayr	1339	jmp .final_processing
		1340
		1341	.fin_timed:
		1342
		1343	jmp .final_processing
		1344
1514	hidnplayr	1345	.no_fin:
		1346
		1347	;-----------------
		1348	; Final processing
		1349
		1350	.final_processing:
		1351
		1352	DEBUGF 1,"Final processing\n"
		1353
1533	hidnplayr	1354	mov [ebx + SOCKET.lock], 0
		1355
1514	hidnplayr	1356	;;; if debug enabled, output packet
		1357
		1358	;test ;;;needoutput = 1
		1359	;jnz .outputnow
		1360
		1361	test [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1529	hidnplayr	1362	jnz .ack_now
1514	hidnplayr	1363
1529	hidnplayr	1364	call kernel_free
		1365	add esp, 4
		1366	ret
		1367
		1368	.ack_now:
		1369
		1370	DEBUGF 1,"ACK now!\n"
		1371
		1372	push ebx
		1373	mov eax, ebx
1514	hidnplayr	1374	call TCP_output
1529	hidnplayr	1375	pop ebx
1514	hidnplayr	1376
1274	hidnplayr	1377	call kernel_free
1529	hidnplayr	1378	add esp, 4
		1379	ret
1274	hidnplayr	1380
1514	hidnplayr	1381	;------------------------------------------
		1382	; Generate an ACK, droping incoming segment
1274	hidnplayr	1383
1514	hidnplayr	1384	align 4
		1385	.drop_after_ack:
1274	hidnplayr	1386
1514	hidnplayr	1387	DEBUGF 1,"Drop after ACK\n"
1274	hidnplayr	1388
1514	hidnplayr	1389	test [edx + TCP_segment.Flags], TH_RST
		1390	jnz .drop
1274	hidnplayr	1391
1514	hidnplayr	1392	and [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1274	hidnplayr	1393
1529	hidnplayr	1394	push ebx
		1395	mov eax, ebx
1514	hidnplayr	1396	call TCP_output
1529	hidnplayr	1397	pop ebx
1318	hidnplayr	1398
1514	hidnplayr	1399	call kernel_free
1529	hidnplayr	1400	add esp, 4
		1401	ret
1274	hidnplayr	1402
1514	hidnplayr	1403
		1404	;-------------------------------------------
		1405	; Generate an RST, dropping incoming segment
		1406
		1407	align 4
		1408	.drop_with_reset:
		1409
		1410	DEBUGF 1,"Drop with reset\n"
		1411
		1412	test [edx + TCP_segment.Flags], TH_RST
		1413	jnz .drop
		1414
		1415	;;; if its a multicast/broadcast, also drop
		1416
		1417	test [edx + TCP_segment.Flags], TH_ACK
		1418	jnz .respond_ack
		1419
		1420	test [edx + TCP_segment.Flags], TH_SYN
		1421	jnz .respond_syn
		1422
		1423	call kernel_free
1529	hidnplayr	1424	add esp, 4
		1425	ret
1514	hidnplayr	1426
		1427	.respond_ack:
		1428
1533	hidnplayr	1429	mov dl, TH_RST
1514	hidnplayr	1430
1533	hidnplayr	1431	push ebx
1529	hidnplayr	1432	call TCP_respond_segment
1533	hidnplayr	1433	pop ebx
1514	hidnplayr	1434
		1435	jmp .destroy_new_socket
		1436
		1437
		1438	.respond_syn:
		1439
1533	hidnplayr	1440	mov dl, TH_RST + TH_ACK
1514	hidnplayr	1441
1533	hidnplayr	1442	push ebx
		1443	call TCP_respond_socket
		1444	pop ebx
1514	hidnplayr	1445
		1446	jmp .destroy_new_socket
		1447
		1448	;-----
		1449	; Drop
		1450
		1451	align 4
		1452	.drop:
		1453
		1454	DEBUGF 1,"Dropping packet\n"
		1455
		1456	;;;; If debugging options are enabled, output the packet somwhere
		1457
		1458	.destroy_new_socket:
		1459
		1460	;;;; kill the newly created socket
		1461
		1462	call kernel_free
1529	hidnplayr	1463	add esp, 4
		1464	ret
1514	hidnplayr	1465
		1466
		1467
		1468
		1469
		1470
		1471	;---------------------------
		1472	;
		1473	; TCP_pull_out_of_band
		1474	;
		1475	; IN: eax =
		1476	; ebx = socket ptr
		1477	; edx = tcp packet ptr
		1478	;
		1479	; OUT: /
		1480	;
		1481	;---------------------------
		1482
		1483	align 4
		1484	TCP_pull_out_of_band:
		1485
		1486	DEBUGF 1,"TCP_pull_out_of_band\n"
		1487
		1488	;;;; 1282-1305
		1489
1318	hidnplayr	1490	ret
		1491
		1492
		1493
		1494	;-----------------------------------------------------------------
		1495	;
1514	hidnplayr	1496	; TCP_output
1318	hidnplayr	1497	;
1519	hidnplayr	1498	; IN: eax = socket pointer
1514	hidnplayr	1499	;
1318	hidnplayr	1500	; OUT: /
		1501	;
		1502	;-----------------------------------------------------------------
		1503	align 4
1514	hidnplayr	1504	TCP_output:
1318	hidnplayr	1505
1514	hidnplayr	1506	DEBUGF 1,"TCP_output, socket: %x\n", eax
1318	hidnplayr	1507
1514	hidnplayr	1508	; We'll detect the length of the data to be transmitted, and flags to be used
		1509	; If there is some data, or any critical controls to send (SYN / RST), then transmit
		1510	; Otherwise, investigate further
1318	hidnplayr	1511
1514	hidnplayr	1512	mov ebx, [eax + TCP_SOCKET.SND_MAX]
		1513	cmp ebx, [eax + TCP_SOCKET.SND_UNA]
		1514	jne .not_idle
1318	hidnplayr	1515
1514	hidnplayr	1516	mov ebx, [eax + TCP_SOCKET.t_idle]
		1517	cmp ebx, [eax + TCP_SOCKET.t_rxtcur]
		1518	jle .not_idle
1318	hidnplayr	1519
1514	hidnplayr	1520	; We have been idle for a while and no ACKS are expected to clock out any data we send..
		1521	; Slow start to get ack "clock" running again.
1318	hidnplayr	1522
1514	hidnplayr	1523	mov ebx, [eax + TCP_SOCKET.t_maxseg]
		1524	mov [eax + TCP_SOCKET.SND_CWND], ebx
1318	hidnplayr	1525
1514	hidnplayr	1526	.not_idle:
		1527	.again:
		1528	mov ebx, [eax + TCP_SOCKET.SND_NXT] ; calculate offset
		1529	sub ebx, [eax + TCP_SOCKET.SND_UNA] ;
1318	hidnplayr	1530
1514	hidnplayr	1531	mov ecx, [eax + TCP_SOCKET.SND_WND] ; determine window
		1532	cmp ecx, [eax + TCP_SOCKET.SND_CWND] ;
		1533	jl @f ;
		1534	mov ecx, [eax + TCP_SOCKET.SND_CWND] ;
		1535	@@: ;
1318	hidnplayr	1536
1529	hidnplayr	1537	call TCP_outflags ; in dl
1318	hidnplayr	1538
1514	hidnplayr	1539	; If in persist timeout with window of 0, send 1 byte.
		1540	; Otherwise, if window is small but nonzero, and timer expired,
		1541	; we will send what we can and go to transmit state
1318	hidnplayr	1542
1514	hidnplayr	1543	test [eax + TCP_SOCKET.t_force], -1
		1544	jz .no_persist_timeout
1318	hidnplayr	1545
1514	hidnplayr	1546	test ecx, ecx
		1547	jnz .no_zero_window
1255	hidnplayr	1548
1533	hidnplayr	1549	cmp ebx, [eax + STREAM_SOCKET.snd + RING_BUFFER.size]
1514	hidnplayr	1550	jge @f
1255	hidnplayr	1551
1514	hidnplayr	1552	and dl, not (TH_FIN) ; clear the FIN flag ??? how can it be set before?
1255	hidnplayr	1553
1514	hidnplayr	1554	@@:
		1555	inc ecx
		1556	jmp .no_persist_timeout
1255	hidnplayr	1557
1514	hidnplayr	1558	.no_zero_window:
1254	hidnplayr	1559
1529	hidnplayr	1560	mov [eax + TCP_SOCKET.timer_persist], 0 ;;;;
1514	hidnplayr	1561	mov [eax + TCP_SOCKET.t_rxtshift], 0
1254	hidnplayr	1562
1514	hidnplayr	1563	.no_persist_timeout:
1159	hidnplayr	1564
1514	hidnplayr	1565	;;;106
1159	hidnplayr	1566
1533	hidnplayr	1567	mov esi, [eax + STREAM_SOCKET.snd + RING_BUFFER.size]
1514	hidnplayr	1568	cmp esi, ecx
		1569	jl @f
		1570	mov esi, ecx
		1571	@@:
		1572	sub esi, ebx
1254	hidnplayr	1573
1514	hidnplayr	1574	cmp esi, -1
		1575	jne .not_minus_one
1159	hidnplayr	1576
1514	hidnplayr	1577	; If FIN has been set, but not ACKed, and we havent been called to retransmit,
		1578	; len (esi) will be -1
		1579	; Otherwise, window shrank after we sent into it.
		1580	; If window shrank to 0, cancel pending retransmit and pull SND_NXT back to (closed) window
		1581	; We will enter persist state below.
		1582	; If window didn't close completely, just wait for an ACK
1159	hidnplayr	1583
1514	hidnplayr	1584	xor esi, esi
1159	hidnplayr	1585
1514	hidnplayr	1586	test ecx, ecx
		1587	jnz @f
1159	hidnplayr	1588
1529	hidnplayr	1589	mov [eax + TCP_SOCKET.timer_retransmission], 0 ; cancel retransmit
1274	hidnplayr	1590
1514	hidnplayr	1591	push [eax + TCP_SOCKET.SND_UNA]
		1592	pop [eax + TCP_SOCKET.SND_NXT]
		1593	@@:
1254	hidnplayr	1594
1514	hidnplayr	1595	.not_minus_one:
1254	hidnplayr	1596
1514	hidnplayr	1597	;;; 124
1159	hidnplayr	1598
1514	hidnplayr	1599	cmp esi, [eax + TCP_SOCKET.t_maxseg]
		1600	jle @f
1274	hidnplayr	1601
1514	hidnplayr	1602	mov esi, [eax + TCP_SOCKET.t_maxseg]
		1603	;sendalot = 1
1274	hidnplayr	1604
1514	hidnplayr	1605	@@:
1274	hidnplayr	1606
1514	hidnplayr	1607	;;; 128
1274	hidnplayr	1608
1514	hidnplayr	1609	mov edi, [eax + TCP_SOCKET.SND_NXT]
		1610	add edi, esi ; len
		1611	sub edi, [eax + TCP_SOCKET.SND_UNA]
1533	hidnplayr	1612	add edi, [eax + STREAM_SOCKET.snd + RING_BUFFER.size]
1514	hidnplayr	1613	cmp edi, 0
		1614	jle @f
1274	hidnplayr	1615
1514	hidnplayr	1616	and dl, not (TH_FIN) ; clear the FIN flag
1159	hidnplayr	1617
1514	hidnplayr	1618	@@:
1159	hidnplayr	1619
		1620
1529	hidnplayr	1621	; set ecx to space available in receive buffer
		1622	; From now on, ecx will be the window we advertise to the other end
1159	hidnplayr	1623
1529	hidnplayr	1624	mov ecx, SOCKET_MAXDATA
1533	hidnplayr	1625	sub ecx, [eax + STREAM_SOCKET.rcv + RING_BUFFER.size]
1159	hidnplayr	1626
1514	hidnplayr	1627	;------------------------------
		1628	; Sender silly window avoidance
1159	hidnplayr	1629
1529	hidnplayr	1630	cmp ecx, [eax + TCP_SOCKET.t_maxseg]
1514	hidnplayr	1631	je .send
1274	hidnplayr	1632
1514	hidnplayr	1633	;;; TODO: 144-145
1274	hidnplayr	1634
1514	hidnplayr	1635	test [eax + TCP_SOCKET.t_force], -1
		1636	jnz .send
1274	hidnplayr	1637
1529	hidnplayr	1638	mov ebx, [eax + TCP_SOCKET.max_sndwnd]
		1639	shr ebx, 1
		1640	cmp ecx, ebx
		1641	jge .send
1274	hidnplayr	1642
1529	hidnplayr	1643	mov ebx, [eax + TCP_SOCKET.SND_NXT]
		1644	cmp ebx, [eax + TCP_SOCKET.SND_MAX]
		1645	jl .send
1254	hidnplayr	1646
1514	hidnplayr	1647	;----------------------------------------
		1648	; Check if a window update should be sent
1159	hidnplayr	1649
1529	hidnplayr	1650	test ecx, ecx ; window
		1651	jz .no_window
1159	hidnplayr	1652
1514	hidnplayr	1653	;;; TODO 154-172
1159	hidnplayr	1654
1514	hidnplayr	1655	.no_window:
1159	hidnplayr	1656
1514	hidnplayr	1657	;--------------------------
		1658	; Should a segment be sent?
1159	hidnplayr	1659
1534	hidnplayr	1660	test [eax + TCP_SOCKET.t_flags], TF_ACKNOW
1514	hidnplayr	1661	jnz .send
1159	hidnplayr	1662
1514	hidnplayr	1663	test dl, TH_SYN + TH_RST
		1664	jnz .send
1159	hidnplayr	1665
1534	hidnplayr	1666	mov ebx, [eax + TCP_SOCKET.SND_UP]
		1667	cmp ebx, [eax + TCP_SOCKET.SND_UNA]
1514	hidnplayr	1668	jg .send
1249	hidnplayr	1669
1514	hidnplayr	1670	test dl, TH_FIN
		1671	jz .enter_persist
1318	hidnplayr	1672
1534	hidnplayr	1673	test [eax + TCP_SOCKET.t_flags], TF_SENTFIN
1514	hidnplayr	1674	jnz .send
1254	hidnplayr	1675
1534	hidnplayr	1676	mov ebx, [eax + TCP_SOCKET.SND_NXT]
		1677	cmp ebx, [eax + TCP_SOCKET.SND_UNA]
1514	hidnplayr	1678	je .send
1254	hidnplayr	1679
1514	hidnplayr	1680	;--------------------
		1681	; Enter persist state
1318	hidnplayr	1682
1514	hidnplayr	1683	.enter_persist:
1318	hidnplayr	1684
1519	hidnplayr	1685	DEBUGF 1,"Entering persist state\n"
1318	hidnplayr	1686
1514	hidnplayr	1687	;--------------------------------------
		1688	; No reason to send a segment, just ret
1318	hidnplayr	1689
1514	hidnplayr	1690	DEBUGF 1,"No reason to send a segment\n"
1318	hidnplayr	1691
1514	hidnplayr	1692	ret
1318	hidnplayr	1693
		1694
1514	hidnplayr	1695	;-----------------------------------------------
		1696	;
		1697	; Send a segment
		1698	;
1529	hidnplayr	1699	; eax = socket pointer
1514	hidnplayr	1700	; dl = flags
		1701	;
		1702	;-----------------------------------------------
1318	hidnplayr	1703
1529	hidnplayr	1704	.send:
1318	hidnplayr	1705
1514	hidnplayr	1706	DEBUGF 1,"Preparing to send a segment\n"
1318	hidnplayr	1707
1529	hidnplayr	1708	mov edi, TCP_segment.Data ; edi will contain headersize
1318	hidnplayr	1709
1529	hidnplayr	1710	sub esp, 8 ; create some space on stack
		1711	push eax ; save this too..
		1712
1514	hidnplayr	1713	;------------------------------------
		1714	; Send options with first SYN segment
1318	hidnplayr	1715
1514	hidnplayr	1716	test dl, TH_SYN
		1717	jz .no_options
1318	hidnplayr	1718
1529	hidnplayr	1719	push [eax + TCP_SOCKET.ISS]
		1720	pop [eax + TCP_SOCKET.SND_NXT]
1318	hidnplayr	1721
1529	hidnplayr	1722	test [eax + TCP_SOCKET.t_flags], TF_NOOPT
1514	hidnplayr	1723	jnz .no_options
1318	hidnplayr	1724
1529	hidnplayr	1725	mov ecx, 1460
		1726	or ecx, TCP_OPT_MAXSEG shl 24 + 4 shl 16
		1727	bswap ecx
		1728	push ecx
		1729	add di, 4
1514	hidnplayr	1730
1529	hidnplayr	1731	test [eax + TCP_SOCKET.t_flags], TF_REQ_SCALE
1514	hidnplayr	1732	jz .no_syn
		1733
		1734	test dl, TH_ACK
		1735	jnz .scale_opt
		1736
1529	hidnplayr	1737	test [eax + TCP_SOCKET.t_flags], TF_RCVD_SCALE
1514	hidnplayr	1738	jz .no_syn
		1739
		1740	.scale_opt:
1529	hidnplayr	1741	movzx ecx, byte [eax + TCP_SOCKET.request_r_scale]
		1742	or ecx, TCP_OPT_WINDOW shl 24 + 4 shl 16 + TCP_OPT_NOP shl 8
		1743	bswap ecx
		1744	pushd ecx
1514	hidnplayr	1745	add di, 4
1159	hidnplayr	1746
1514	hidnplayr	1747	.no_syn:
1159	hidnplayr	1748
1514	hidnplayr	1749	;------------------------------------
		1750	; Make the timestamp option if needed
1159	hidnplayr	1751
1529	hidnplayr	1752	test [eax + TCP_SOCKET.t_flags], TF_REQ_TSTMP
1514	hidnplayr	1753	jz .no_timestamp
1159	hidnplayr	1754
1514	hidnplayr	1755	test dl, TH_RST
		1756	jnz .no_timestamp
		1757
		1758	test dl, TH_ACK
		1759	jz .timestamp
		1760
1529	hidnplayr	1761	test [eax + TCP_SOCKET.t_flags], TF_RCVD_TSTMP
1514	hidnplayr	1762	jz .no_timestamp
		1763
		1764	.timestamp:
1529	hidnplayr	1765	mov esi, [timer_ticks]
		1766	bswap esi
		1767	push esi
1514	hidnplayr	1768	pushw 0
1529	hidnplayr	1769	pushd TCP_OPT_TIMESTAMP + 10 shl 8 + TCP_OPT_NOP shl 16 + TCP_OPT_NOP shl 24
1514	hidnplayr	1770	add di, 10
		1771
		1772	.no_timestamp:
		1773	;; TODO: check if we dont exceed the max segment size
		1774
		1775	.no_options:
1529	hidnplayr	1776	; eax = socket ptr
		1777	; edx = flags
		1778	; ecx = data size
		1779	; edi = header size
		1780	; esi = snd ring buff ptr
1514	hidnplayr	1781
1533	hidnplayr	1782	mov ecx, [eax + STREAM_SOCKET.snd + RING_BUFFER.size]
		1783	cmp ecx, [eax + TCP_SOCKET.t_maxseg] ;;; right?
		1784	jle @f
		1785	mov ecx, [eax + TCP_SOCKET.t_maxseg]
		1786	@@:
1514	hidnplayr	1787	add ecx, edi ; total TCP segment size
		1788
1529	hidnplayr	1789	; Start by pushing all TCP header values in reverse order on stack
		1790	; (essentially, creating the tcp header!)
1514	hidnplayr	1791
1529	hidnplayr	1792	pushw 0 ; .UrgentPointer dw ?
		1793	pushw 0 ; .Checksum dw ?
		1794	pushw 0x00a0 ; .Window dw ? ;;;;;;;
		1795	shl edi, 2 ; .DataOffset db ? only 4 left-most bits
		1796	shl dx, 8
		1797	or dx, di ; .Flags db ?
		1798	pushw dx
		1799	shr edi, 2 ; .DataOffset db ? ;;;;
1514	hidnplayr	1800
1529	hidnplayr	1801	push [eax + TCP_SOCKET.RCV_NXT] ; .AckNumber dd ?
		1802	ntohld [esp]
1159	hidnplayr	1803
1529	hidnplayr	1804	push [eax + TCP_SOCKET.SND_NXT] ; .SequenceNumber dd ?
		1805	ntohld [esp]
1159	hidnplayr	1806
1529	hidnplayr	1807	push [eax + TCP_SOCKET.RemotePort] ; .DestinationPort dw ?
		1808	ntohlw [esp]
1249	hidnplayr	1809
1529	hidnplayr	1810	push [eax + TCP_SOCKET.LocalPort] ; .SourcePort dw ?
		1811	ntohlw [esp]
1274	hidnplayr	1812
1533	hidnplayr	1813	push edi ; header size
1274	hidnplayr	1814
1529	hidnplayr	1815	; Create the IP packet
		1816	mov ebx, [eax + IP_SOCKET.LocalIP] ; source ip
		1817	mov eax, [eax + IP_SOCKET.RemoteIP] ; dest ip
		1818	mov di, IP_PROTO_TCP shl 8 + 128
		1819	call IPv4_output
		1820	jz .fail
1274	hidnplayr	1821
1529	hidnplayr	1822	;-----------------------------------------
		1823	; Move TCP header from stack to TCP packet
1274	hidnplayr	1824
1533	hidnplayr	1825	push ecx
		1826	mov ecx, [esp+4]
		1827	lea esi, [esp+4+4]
1529	hidnplayr	1828	shr ecx, 2
		1829	rep movsd
1533	hidnplayr	1830	pop ecx ; full TCP packet size
1274	hidnplayr	1831
1533	hidnplayr	1832	pop esi ; headersize
		1833	add esp, esi
1254	hidnplayr	1834
1533	hidnplayr	1835	mov [esp + 4], eax ; packet ptr
1530	hidnplayr	1836	mov [esp + 4+4], edx ; packet size
1254	hidnplayr	1837
1533	hidnplayr	1838	mov edx, edi ; begin of data
		1839	sub edx, esi ; begin of packet (edi = begin of data)
		1840	push ecx
		1841	sub ecx, esi ; data size
1159	hidnplayr	1842
1514	hidnplayr	1843	;--------------
		1844	; Copy the data
1159	hidnplayr	1845
1529	hidnplayr	1846	; eax = ptr to ring struct
		1847	; ecx = buffer size
		1848	; edi = ptr to buffer
1249	hidnplayr	1849
1536	hidnplayr	1850	; test ecx, ecx
1533	hidnplayr	1851	mov eax, [esp+4] ; socket ptr
1536	hidnplayr	1852	add [eax + TCP_SOCKET.SND_NXT], ecx
		1853	add eax, STREAM_SOCKET.snd
1533	hidnplayr	1854	push edx
1529	hidnplayr	1855	call SOCKET_ring_read
1536	hidnplayr	1856	pop esi
		1857	pop ecx
1529	hidnplayr	1858	pop eax
1254	hidnplayr	1859
1533	hidnplayr	1860	test [esi + TCP_segment.Flags], TH_SYN + TH_FIN
		1861	jz @f
		1862	inc [eax + TCP_SOCKET.SND_NXT]
		1863	;;; TODO: update sentfin flag
		1864	@@:
1254	hidnplayr	1865
1533	hidnplayr	1866	mov edx, [eax + TCP_SOCKET.SND_NXT]
		1867	cmp edx, [eax + TCP_SOCKET.SND_MAX]
		1868	jle @f
		1869	mov [eax + TCP_SOCKET.SND_MAX], edx
		1870
		1871	;;;; TODO: time transmission (420)
		1872	@@:
		1873
		1874	;;; TODO: set retransmission timer
		1875
		1876	;--------------------
		1877	; Create the checksum
		1878
1529	hidnplayr	1879	DEBUGF 1,"checksum: ptr=%x size=%u\n", esi, ecx
1159	hidnplayr	1880
1529	hidnplayr	1881	TCP_checksum (eax + IP_SOCKET.LocalIP), (eax + IP_SOCKET.RemoteIP)
		1882	mov [esi+TCP_segment.Checksum], dx
		1883
1514	hidnplayr	1884	;----------------
		1885	; Send the packet
1159	hidnplayr	1886
1529	hidnplayr	1887	DEBUGF 1,"Sending TCP Packet to device %x\n", ebx
		1888	call [ebx + NET_DEVICE.transmit]
		1889	ret
1159	hidnplayr	1890
1514	hidnplayr	1891
1529	hidnplayr	1892	.fail:
		1893	pop ecx
		1894	add esp, ecx
1536	hidnplayr	1895	add esp, 4+8
1529	hidnplayr	1896	DEBUGF 1,"TCP_output: failed\n"
1159	hidnplayr	1897	ret
		1898
1529	hidnplayr	1899
		1900
1514	hidnplayr	1901	;-------------------------
		1902	;
		1903	; TCP_outflags
		1904	;
		1905	; IN: eax = socket ptr
		1906	;
		1907	; OUT: edx = flags
		1908	;
		1909	;-------------------------
1249	hidnplayr	1910	align 4
1514	hidnplayr	1911	TCP_outflags:
1254	hidnplayr	1912
1514	hidnplayr	1913	mov edx, [eax + TCP_SOCKET.t_state]
		1914	movzx edx, byte [edx + .flaglist]
1254	hidnplayr	1915
1514	hidnplayr	1916	DEBUGF 1,"TCP_outflags, socket: %x, flags: %x\n", eax, dl
		1917
1159	hidnplayr	1918	ret
		1919
1514	hidnplayr	1920	.flaglist:
1159	hidnplayr	1921
1514	hidnplayr	1922	db TH_RST + TH_ACK ; TCB_CLOSED
		1923	db 0 ; TCB_LISTEN
		1924	db TH_SYN ; TCB_SYN_SENT
		1925	db TH_SYN + TH_ACK ; TCB_SYN_RECEIVED
		1926	db TH_ACK ; TCB_ESTABLISHED
		1927	db TH_ACK ; TCB_CLOSE_WAIT
		1928	db TH_SYN + TH_ACK ; TCB_FIN_WAIT_1
		1929	db TH_SYN + TH_ACK ; TCB_CLOSING
		1930	db TH_SYN + TH_ACK ; TCB_LAST_ACK
		1931	db TH_ACK ; TCB_FIN_WAIT_2
		1932	db TH_ACK ; TCB_TIMED_WAIT
1249	hidnplayr	1933
1514	hidnplayr	1934
1529	hidnplayr	1935
		1936
1514	hidnplayr	1937	;-------------------------
		1938	;
		1939	; TCP_drop
		1940	;
		1941	; IN: eax = socket ptr
		1942	;
		1943	; OUT: /
		1944	;
		1945	;-------------------------
1249	hidnplayr	1946	align 4
1514	hidnplayr	1947	TCP_drop:
1254	hidnplayr	1948
1514	hidnplayr	1949	DEBUGF 1,"TCP_drop\n"
1254	hidnplayr	1950
1514	hidnplayr	1951	; cmp [eax + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		1952	; jl .no_syn_received
1159	hidnplayr	1953
1514	hidnplayr	1954	mov [eax + TCP_SOCKET.t_state], TCB_CLOSED
1159	hidnplayr	1955
1514	hidnplayr	1956	call TCP_output
1254	hidnplayr	1957
1514	hidnplayr	1958	; .no_syn_received:
		1959
1159	hidnplayr	1960	ret
		1961
		1962
1254	hidnplayr	1963
		1964
1159	hidnplayr	1965
1514	hidnplayr	1966	;---------------------------------------
		1967	;
1519	hidnplayr	1968	; The easy way to send an ACK/RST/keepalive segment
1514	hidnplayr	1969	;
1529	hidnplayr	1970	; TCP_respond_socket:
		1971	;
		1972	; IN: ebx = socket ptr
1519	hidnplayr	1973	; cl = flags
1514	hidnplayr	1974	;
1529	hidnplayr	1975	;--------------------------------------
1514	hidnplayr	1976	align 4
1529	hidnplayr	1977	TCP_respond_socket:
1254	hidnplayr	1978
1529	hidnplayr	1979	DEBUGF 1,"TCP_respond_socket\n"
1159	hidnplayr	1980
1519	hidnplayr	1981	;---------------------
		1982	; Create the IP packet
		1983
1529	hidnplayr	1984	push cx ebx
		1985	mov eax, [ebx + IP_SOCKET.RemoteIP]
		1986	mov ebx, [ebx + IP_SOCKET.LocalIP]
1519	hidnplayr	1987	mov ecx, TCP_segment.Data
1529	hidnplayr	1988	mov di , IP_PROTO_TCP shl 8 + 128
		1989	call IPv4_output
1519	hidnplayr	1990	test edi, edi
		1991	jz .error
1529	hidnplayr	1992	pop esi cx
		1993	push edx eax
1519	hidnplayr	1994
1529	hidnplayr	1995	;-----------------------------------------------
		1996	; Fill in the TCP header by using the socket ptr
1519	hidnplayr	1997
1529	hidnplayr	1998	mov ax, [esi + TCP_SOCKET.LocalPort]
		1999	rol ax, 8
		2000	stosw
		2001	mov ax, [esi + TCP_SOCKET.RemotePort]
		2002	rol ax, 8
		2003	stosw
		2004	mov eax, [esi + TCP_SOCKET.SND_NXT]
		2005	bswap eax
		2006	stosd
		2007	mov eax, [esi + TCP_SOCKET.RCV_NXT]
		2008	bswap eax
		2009	stosd
		2010	mov al, 0x50 ; Dataoffset: 20 bytes
		2011	stosb
		2012	mov al, cl
		2013	stosb
		2014	mov ax, [esi + TCP_SOCKET.RCV_WND]
		2015	rol ax, 8
		2016	stosw ; window
		2017	xor eax, eax
		2018	stosd ; checksum + urgentpointer
1519	hidnplayr	2019
		2020	;---------------------
		2021	; Fill in the checksum
		2022
		2023	.checksum:
1529	hidnplayr	2024	sub edi, TCP_segment.Data
		2025	mov ecx, TCP_segment.Data
		2026	xchg esi, edi
		2027	TCP_checksum (edi + IP_SOCKET.LocalIP), (esi + IP_SOCKET.RemoteIP)
		2028	mov [esi+TCP_segment.Checksum], dx
1519	hidnplayr	2029
		2030	;--------------------
		2031	; And send the segment
		2032
		2033	call [ebx + NET_DEVICE.transmit]
1159	hidnplayr	2034	ret
		2035
1519	hidnplayr	2036	.error:
1529	hidnplayr	2037	DEBUGF 1,"TCP_respond failed\n"
		2038	add esp, 2+4
1159	hidnplayr	2039
1519	hidnplayr	2040	ret
1514	hidnplayr	2041
1529	hidnplayr	2042
		2043
		2044	;-------------------------
		2045	; TCP_respond.segment:
		2046	;
		2047	; IN: edx = segment ptr (a previously received segment)
		2048	; cl = flags
		2049
		2050	align 4
		2051	TCP_respond_segment:
		2052
		2053	DEBUGF 1,"TCP_respond_segment\n"
		2054
		2055	;---------------------
		2056	; Create the IP packet
		2057
		2058	push cx edx
		2059	mov ebx, [edx - 20 + IPv4_Packet.SourceAddress] ;;;; and what if ip packet had options?!
		2060	mov eax, [edx - 20 + IPv4_Packet.DestinationAddress] ;;;
		2061	mov ecx, TCP_segment.Data
		2062	mov di , IP_PROTO_TCP shl 8 + 128
		2063	call IPv4_output
		2064	jz .error
1533	hidnplayr	2065	pop esi cx
1529	hidnplayr	2066
		2067	push edx eax
		2068
1519	hidnplayr	2069	;---------------------------------------------------
		2070	; Fill in the TCP header by using a received segment
		2071
		2072	mov ax, [esi + TCP_segment.DestinationPort]
		2073	rol ax, 8
		2074	stosw
		2075	mov ax, [esi + TCP_segment.SourcePort]
		2076	rol ax, 8
		2077	stosw
		2078	mov eax, [esi + TCP_segment.AckNumber]
		2079	bswap eax
		2080	stosd
		2081	xor eax, eax
		2082	stosd
		2083	mov al, 0x50 ; Dataoffset: 20 bytes
		2084	stosb
		2085	mov al, cl
		2086	stosb
		2087	mov ax, 1280
		2088	rol ax, 8
		2089	stosw ; window
		2090	xor eax, eax
		2091	stosd ; checksum + urgentpointer
		2092
1529	hidnplayr	2093	;---------------------
		2094	; Fill in the checksum
1519	hidnplayr	2095
1529	hidnplayr	2096	.checksum:
		2097	lea esi, [edi - TCP_segment.Data]
		2098	mov ecx, TCP_segment.Data
		2099	TCP_checksum (esi - 20 + IPv4_Packet.DestinationAddress), (esi - 20 + IPv4_Packet.DestinationAddress)
		2100	mov [esi+TCP_segment.Checksum], dx
1519	hidnplayr	2101
1529	hidnplayr	2102	;--------------------
		2103	; And send the segment
1519	hidnplayr	2104
1529	hidnplayr	2105	call [ebx + NET_DEVICE.transmit]
		2106	ret
1519	hidnplayr	2107
1529	hidnplayr	2108	.error:
		2109	DEBUGF 1,"TCP_respond failed\n"
		2110	add esp, 2+4
1519	hidnplayr	2111
		2112	ret
		2113
		2114
		2115
1254	hidnplayr	2116
		2117	;---------------------------------------------------------------------------
		2118	;
		2119	; TCP_API
		2120	;
		2121	; This function is called by system function 75
		2122	;
		2123	; IN: subfunction number in bl
		2124	; device number in bh
		2125	; ecx, edx, .. depends on subfunction
		2126	;
		2127	; OUT:
		2128	;
		2129	;---------------------------------------------------------------------------
		2130	align 4
		2131	TCP_API:
		2132
		2133	movzx eax, bh
		2134	shl eax, 2
		2135
		2136	test bl, bl
		2137	jz .packets_tx ; 0
		2138	dec bl
		2139	jz .packets_rx ; 1
		2140
		2141	.error:
		2142	mov eax, -1
		2143	ret
		2144
		2145	.packets_tx:
1514	hidnplayr	2146	add eax, TCP_segments_tx
1254	hidnplayr	2147	mov eax, [eax]
		2148	ret
		2149
		2150	.packets_rx:
1514	hidnplayr	2151	add eax, TCP_segments_rx
1254	hidnplayr	2152	mov eax, [eax]
		2153	ret

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(root)/kernel/branches/net/network/tcp.inc – Rev 1536