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: 1519 $
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
		76
1514	hidnplayr	77	struct TCP_segment
1159	hidnplayr	78	.SourcePort dw ?
		79	.DestinationPort dw ?
		80	.SequenceNumber dd ?
		81	.AckNumber dd ?
1196	hidnplayr	82	.DataOffset db ? ; DataOffset[0-3 bits] and Reserved[4-7]
		83	.Flags db ? ; Reserved[0-1 bits]\|URG\|ACK\|PSH\|RST\|SYN\|FIN
1159	hidnplayr	84	.Window dw ?
		85	.Checksum dw ?
		86	.UrgentPointer dw ?
1514	hidnplayr	87	.Data: ; ..or options
1159	hidnplayr	88	ends
		89
1274	hidnplayr	90	struct tcp_in_queue_entry
		91	.data_ptr dd ?
		92	.data_size dd ?
1514	hidnplayr	93	.offset dd ?
1274	hidnplayr	94	.size:
		95	ends
		96
		97	struct tcp_out_queue_entry
		98	.data_ptr dd ?
		99	.data_size dd ?
1514	hidnplayr	100
1274	hidnplayr	101	.size:
		102	ends
		103
1196	hidnplayr	104	align 4
		105	uglobal
1514	hidnplayr	106	TCP_segments_tx rd IP_MAX_INTERFACES
		107	TCP_segments_rx rd IP_MAX_INTERFACES
		108	TCP_bytes_rx rq IP_MAX_INTERFACES
		109	TCP_bytes_tx rq IP_MAX_INTERFACES
		110	TCP_sequence_num dd ?
1196	hidnplayr	111	endg
		112
		113
		114	;-----------------------------------------------------------------
		115	;
		116	; TCP_init
		117	;
		118	; This function resets all TCP variables
		119	;
		120	; IN: /
		121	; OUT: /
		122	;
		123	;-----------------------------------------------------------------
		124	align 4
		125	TCP_init:
		126
		127	xor eax, eax
1514	hidnplayr	128	mov edi, TCP_segments_tx
		129	mov ecx, (6*IP_MAX_INTERFACES)
1196	hidnplayr	130	rep stosd
		131
1519	hidnplayr	132	mov [TCP_sequence_num], 1
1196	hidnplayr	133
		134	ret
		135
		136
1519	hidnplayr	137	;----------------------
1196	hidnplayr	138	;
1159	hidnplayr	139	;
1519	hidnplayr	140	;----------------------
1196	hidnplayr	141	align 4
1519	hidnplayr	142	TCP_timer_160ms:
1159	hidnplayr	143
1514	hidnplayr	144	mov eax, net_sockets
		145	.loop:
		146	mov eax, [eax + SOCKET.NextPtr]
		147	or eax, eax
1159	hidnplayr	148	jz .exit
		149
1514	hidnplayr	150	cmp [eax + SOCKET.Type], IP_PROTO_TCP
		151	jne .loop
1249	hidnplayr	152
1519	hidnplayr	153	dec [eax + TCP_SOCKET.timer_ack]
1514	hidnplayr	154	jnz .loop
1159	hidnplayr	155
1519	hidnplayr	156	DEBUGF 1,"TCP ack for socket %x expired, time to piggyback!\n", eax
1159	hidnplayr	157
1519	hidnplayr	158	push eax
		159	call TCP_respond
1514	hidnplayr	160	pop eax
1159	hidnplayr	161
1519	hidnplayr	162	jmp .loop
1159	hidnplayr	163
		164	.exit:
1519	hidnplayr	165
1159	hidnplayr	166	ret
		167
		168
1519	hidnplayr	169	;-----------------------------------------------------------------
1159	hidnplayr	170	;
		171	;
1519	hidnplayr	172	;-----------------------------------------------------------------
1196	hidnplayr	173	align 4
1519	hidnplayr	174	TCP_timer_640ms:
1159	hidnplayr	175
1519	hidnplayr	176	; Update TCP sequence number
		177
1514	hidnplayr	178	add [TCP_sequence_num], 64000
1159	hidnplayr	179
1519	hidnplayr	180	; scan through all the active TCP sockets, decrementing ALL timers
		181	; timers do not have the chance to wrap because of the keepalive timer will kill the socket when it expires
1159	hidnplayr	182
1519	hidnplayr	183	mov eax, net_sockets
		184	.loop:
		185	mov eax, [eax + SOCKET.NextPtr]
		186	.check_only:
		187	or eax, eax
		188	jz .exit
1159	hidnplayr	189
1519	hidnplayr	190	cmp [eax + SOCKET.Type], IP_PROTO_TCP
		191	jne .loop
1159	hidnplayr	192
1519	hidnplayr	193	dec [eax + TCP_SOCKET.timer_retransmission]
		194	jnz .check_more2
1254	hidnplayr	195
1519	hidnplayr	196	DEBUGF 1,"socket %x: Retransmission timer expired\n", eax
1159	hidnplayr	197
1519	hidnplayr	198	push eax
		199	call TCP_output
		200	pop eax
1159	hidnplayr	201
1519	hidnplayr	202	.check_more2:
		203	dec [eax + TCP_SOCKET.timer_keepalive]
		204	jnz .check_more3
1159	hidnplayr	205
1519	hidnplayr	206	DEBUGF 1,"socket %x: Keepalive expired\n", eax
1159	hidnplayr	207
1519	hidnplayr	208	;;; TODO: check socket state and handle accordingly
1318	hidnplayr	209
1519	hidnplayr	210	.check_more3:
		211	dec [eax + TCP_SOCKET.timer_timed_wait]
		212	jnz .check_more5
		213
		214	DEBUGF 1,"socket %x: 2MSL timer expired\n", eax
		215
		216	.check_more5:
		217	dec [eax + TCP_SOCKET.timer_persist]
		218	jnz .loop
		219
		220	DEBUGF 1,"socket %x: persist timer expired\n", eax
		221
		222	jmp .loop
		223	.exit:
		224	ret
		225
		226
1249	hidnplayr	227	;-----------------------------------------------------------------
		228	;
1514	hidnplayr	229	; TCP_input:
1159	hidnplayr	230	;
1514	hidnplayr	231	; IN: [esp] = ptr to buffer
		232	; [esp+4] = buffer size
		233	; ebx = ptr to device struct
		234	; ecx = segment size
		235	; edx = ptr to TCP segment
1196	hidnplayr	236	;
1514	hidnplayr	237	; esi = ipv4 source address
		238	; edi = ipv4 dest address
		239	;
1196	hidnplayr	240	; OUT: /
		241	;
		242	;-----------------------------------------------------------------
1249	hidnplayr	243	align 4
1514	hidnplayr	244	TCP_input:
1159	hidnplayr	245
1514	hidnplayr	246	DEBUGF 1,"TCP_input\n"
1196	hidnplayr	247
1514	hidnplayr	248	; 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	249
1514	hidnplayr	250	movzx eax, [edx + TCP_segment.DataOffset]
		251	and eax, 0xf0
		252	shr al , 2
		253
		254	DEBUGF 1,"data offset: %u\n", eax
		255
		256	cmp eax, 20
		257	jl .drop
		258
		259	cmp eax, ecx
		260	jg .drop
		261
		262	;-------------------------------
		263	; Now, re-calculate the checksum
		264
		265	push eax edx ebx
		266
		267	push edi
		268	push esi
		269	mov esi, edx
		270	call TCP_checksum ; this destroys edx, ecx and esi (but not edi! :)
		271
		272	pop ebx edx eax
		273
		274	cmp [edx + TCP_segment.Checksum], 0
		275	jnz .drop
		276
		277	DEBUGF 1,"Checksum is correct\n"
		278
		279	;-----------------------------------------------------------------------------------------
		280	; Check if this packet has a timestamp option (We do it here so we can process it quickly)
		281
		282	cmp eax, 20 + 12 ; Timestamp option is 12 bytes
		283	jl .no_timestamp
		284	je .is_ok
		285
		286	cmp byte [edx + TCP_segment.Data + 12], 0 ; end of option list
		287	jne .no_timestamp
		288
		289	.is_ok:
		290	test [edx + TCP_segment.Flags], TH_SYN ; SYN flag must not be set
		291	jnz .no_timestamp
		292
		293	cmp dword [edx + TCP_segment.Data], 0x0101080a ; Timestamp header
		294	jne .no_timestamp
		295
		296	DEBUGF 1,"timestamp ok\n"
		297
		298	; TODO: Parse the options
		299	; TODO: Set a Bit in the TCP to tell all options are parsed
		300
		301	ret
		302
		303	.no_timestamp:
		304
		305	;-------------------------------------------
		306	; Convert Big-endian values to little endian
		307
		308	ntohld [edx + TCP_segment.SequenceNumber]
		309	ntohld [edx + TCP_segment.AckNumber]
		310
		311	ntohlw [edx + TCP_segment.Window]
		312	ntohlw [edx + TCP_segment.UrgentPointer]
		313
		314	;------------------------------------------------------------
		315	; Next thing to do is find the TCB (thus, the socket pointer)
		316
1274	hidnplayr	317	; IP Packet TCP Destination Port = local Port
1514	hidnplayr	318	; (IP Packet SenderAddress = Remote IP) OR (Remote IP = 0)
1318	hidnplayr	319	; (IP Packet TCP Source Port = remote Port) OR (remote Port = 0)
1159	hidnplayr	320
		321	mov ebx, net_sockets
		322
1249	hidnplayr	323	.socket_loop:
1514	hidnplayr	324	mov ebx, [ebx + SOCKET.NextPtr]
1159	hidnplayr	325	or ebx, ebx
1514	hidnplayr	326	jz .drop_with_reset
1159	hidnplayr	327
1514	hidnplayr	328	cmp [ebx + SOCKET.Type], IP_PROTO_TCP
1249	hidnplayr	329	jne .socket_loop
1159	hidnplayr	330
1514	hidnplayr	331	mov ax, [edx + TCP_segment.DestinationPort]
		332	cmp [ebx + TCP_SOCKET.LocalPort], ax
		333	jne .socket_loop
		334
		335	mov eax, [ebx + IP_SOCKET.RemoteIP]
1249	hidnplayr	336	cmp eax, esi
		337	je @f
		338	test eax, eax
1514	hidnplayr	339	jnz .socket_loop
1249	hidnplayr	340	@@:
1159	hidnplayr	341
1514	hidnplayr	342	mov ax, [ebx + TCP_SOCKET.RemotePort]
		343	cmp [edx + TCP_segment.SourcePort] , ax
1274	hidnplayr	344	je .found_socket
1249	hidnplayr	345	test ax, ax
1254	hidnplayr	346	jnz .socket_loop
1274	hidnplayr	347	.found_socket:
1514	hidnplayr	348	DEBUGF 1,"Socket ptr: %x\n", ebx
1254	hidnplayr	349
1514	hidnplayr	350	; ebx now contains the pointer to the socket
1257	hidnplayr	351
1514	hidnplayr	352	;----------------------------
		353	; Check if socket isnt closed
		354
		355	cmp [TCP_SOCKET.t_state], TCB_CLOSED
		356	je .drop
		357
		358	;----------------
		359	; Lock the socket
		360
		361	add ebx, SOCKET.lock ; TODO: figure out if we should lock now already
1249	hidnplayr	362	call wait_mutex
1514	hidnplayr	363	sub ebx, SOCKET.lock
1159	hidnplayr	364
1514	hidnplayr	365	;---------------------------------------
		366	; unscale the window into a 32 bit value ;;;;;;
1159	hidnplayr	367
1514	hidnplayr	368	movzx eax, [edx + TCP_segment.Window]
		369	xchg al, ah
		370
		371	test [edx + TCP_segment.Flags], TH_SYN
		372	jnz .no_syn
		373
		374	mov cl , [ebx + TCP_SOCKET.SND_SCALE]
		375	shl eax, cl
		376
		377	.no_syn:
		378
		379	;-----------------------------------
		380	; Is this socket a listening socket?
		381
		382	; If so, create a new socket
		383
		384	test [ebx + SOCKET.options], SO_ACCEPTCON
		385	jz .no_accept_conn
		386
		387
		388	; TODO: create a new socket
		389
		390
		391	.no_accept_conn:
		392
		393	;----------------------------
		394	; Compute window scale factor
		395
		396
		397	; TODO
		398
		399
		400	;-------------------------------------
		401	; Reset idle timer and keepalive timer
		402
1519	hidnplayr	403	;;;; TODO: idle timer?
1514	hidnplayr	404
1519	hidnplayr	405	mov [ebx + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval
1514	hidnplayr	406
		407	;-----------------------------------------
		408	; Process TCP options if not in LISTEN state
		409
		410	test [ebx + TCP_SOCKET.t_state], TCB_LISTEN
		411	jz .dont_do_options
		412
		413	call TCP_do_options
		414
		415	.dont_do_options:
		416
		417	;-----------------------------------------------------------------------
		418	; Time to do some header prediction (Original Principle by Van Jacobson)
		419
		420
		421	; There are two common cases for an uni-directional data transfer.
		422	;
		423	; General rule: the packets has no control flags, is in-sequence,
		424	; window width didnt change and we're not retransmitting.
		425	;
		426	; Second rules:
		427	; - If the length is 0 and the ACK moved forward, we're the sender side of the transfer.
		428	; In this case we'll free the ACK'ed data and notify higher levels that we have free space in buffer
		429	;
		430	; - If the length is not 0 and the ACK didn't move, we're the receiver side of the transfer.
		431	; If the packets are in order (data queue is empty), add the data to the socket buffer and request a delayed ACK
		432
		433	cmp [TCP_SOCKET.t_state], TCB_ESTABLISHED
		434	jnz .not_uni_xfer
		435
		436	test [TCP_segment.Flags], TH_SYN + TH_FIN + TH_RST + TH_URG
		437	jnz .not_uni_xfer
		438
		439	test [TCP_segment.Flags], TH_ACK
		440	jz .not_uni_xfer
		441
		442	mov eax, [edx + TCP_segment.SequenceNumber]
		443	cmp eax, [ebx + TCP_SOCKET.RCV_NXT]
		444	jne .not_uni_xfer
		445
		446	movzx eax, [edx + TCP_segment.Window] ;;;;;
		447	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		448	jne .not_uni_xfer
		449
		450	mov eax, [ebx + TCP_SOCKET.SND_NXT]
		451	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		452	jne .not_uni_xfer
		453
		454	;-------------------------------------------------------------------------------
		455	; If last ACK falls within this segment's sequence number, record the timestamp.
		456
		457	; TODO: check if it has a timestamp
		458
		459
		460
		461
		462	;---------------------------------------
		463	; check if we are sender in the uni-xfer
		464
		465	; If the following 4 conditions are all true, this segment is a pure ACK.
		466	;
		467	; - The segment contains no data (ti_len is 0).
		468
		469	movzx eax, [edx + TCP_segment.DataOffset]
1274	hidnplayr	470	and eax, 11110000b
		471	shr eax, 2
		472	sub ecx, eax
1514	hidnplayr	473	jnz .not_sender
1274	hidnplayr	474
1514	hidnplayr	475	; - The acknowledgment field in the segment (ti_ack) is greater than the largest unacknowledged sequence number (snd_una).
		476	; Since this test is "greater than" and not "greater than or equal to," it is true only if some positive amount of data is acknowledged by the ACK.
1274	hidnplayr	477
1514	hidnplayr	478	mov eax, [edx + TCP_segment.AckNumber]
		479	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
		480	jle .not_uni_xfer
1159	hidnplayr	481
1514	hidnplayr	482	; - The acknowledgment field in the segment (ti_ack) is less than or equal to the maximum sequence number sent (snd_max).
1159	hidnplayr	483
1514	hidnplayr	484	; mov eax, [edx + TCP_segment.Ack]
		485	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		486	jg .not_uni_xfer
1159	hidnplayr	487
1514	hidnplayr	488	; - The congestion window (snd_cwnd) is greater than or equal to the current send window (snd_wnd).
		489	; 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.
1254	hidnplayr	490
1514	hidnplayr	491	mov eax, [ebx + TCP_SOCKET.SND_CWND]
		492	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		493	jl .not_uni_xfer
1318	hidnplayr	494
1514	hidnplayr	495	DEBUGF 1,"Header prediction: we are sender\n"
1274	hidnplayr	496
1514	hidnplayr	497	;---------------------------------
		498	; Packet is a pure ACK, process it
1274	hidnplayr	499
1514	hidnplayr	500	; Update RTT estimators
1159	hidnplayr	501
1514	hidnplayr	502	; Delete acknowledged bytes from send buffer
1254	hidnplayr	503
1514	hidnplayr	504	; Stop retransmit timer
1519	hidnplayr	505	mov [ebx + TCP_SOCKET.timer_ack], 0
1159	hidnplayr	506
1514	hidnplayr	507	; Awaken waiting processes
1519	hidnplayr	508	mov eax, ebx
		509	call SOCKET_notify_owner
1318	hidnplayr	510
1514	hidnplayr	511	; Generate more output
1519	hidnplayr	512	call TCP_output
1254	hidnplayr	513
1514	hidnplayr	514	jmp .drop
1159	hidnplayr	515
1196	hidnplayr	516
		517
		518
1514	hidnplayr	519	;-------------------------------------------------
		520	; maybe we are the receiver in the uni-xfer then..
		521
		522	.not_sender:
		523	; The amount of data in the segment (ti_len) is greater than 0 (data count is in ecx)
		524
		525
		526	; The acknowledgment field (ti_ack) equals the largest unacknowledged sequence number. This means no data is acknowledged by this segment.
		527	mov eax, [edx + TCP_segment.AckNumber]
		528	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
		529	jne .not_uni_xfer
		530
		531	; The reassembly list of out-of-order segments for the connection is empty (seg_next equals tp).
		532	;;;;
		533	jnz .not_uni_xfer
		534
		535	; There is room in the receive buffer for the data in the segment.
		536	;;;;
		537	jnz .not_uni_xfer
		538
		539	;-------------------------------------
		540	; Complete processing of received data
		541
		542	DEBUGF 1,"header prediction: we are receiver\nreceiving %u bytes of data\n", ecx
		543
		544	; The next expected receive sequence number (rcv_nxt) is incremented by the number of bytes of data.
		545
		546	add [ebx + TCP_SOCKET.RCV_NXT], ecx
		547
		548	; Add the data to the socket buffer
1519	hidnplayr	549	mov eax, ebx
		550	;;; mov...
		551	call SOCKET_input
1514	hidnplayr	552
		553	; The delayed-ACK flag is set and the input processing is complete.
		554
		555	jmp .drop
		556
		557
		558
		559
		560
		561	;----------------------------------------------------
		562	; Header prediction failed, doing it the slow way..
		563
		564	.not_uni_xfer:
		565
		566	DEBUGF 1,"Header prediction failed\n"
		567
		568	;------------------------
		569	; calculate header length ;;;;; we already calculated this before!
		570	movzx eax, [edx + TCP_segment.DataOffset]
		571	and eax, 0xf0
		572	shr eax, 2
		573
		574	; Update edx to point to data..
		575	add edx, eax
		576	; ..and ecx to give data size
		577	sub ecx, eax
		578
		579	;------------------------------
		580	; Calculate receive window size
		581
		582	;;;;
		583
		584
		585	;-------------------------
		586	; TCP slow input procedure
		587
		588	DEBUGF 1,"TCP slow input procedure\n"
		589
		590	cmp [eax + TCP_SOCKET.t_state], TCB_LISTEN
		591	je .LISTEN
		592
		593	cmp [eax + TCP_SOCKET.t_state], TCB_SYN_SENT
		594	je .SYN_SENT
		595
		596
		597	;--------------------------------------------
		598	; Protection Against Wrapped Sequence Numbers
		599
		600
		601	; First, check timestamp if present
		602
		603	;;;; TODO
		604
		605	; Then, check if at least some bytes of data are within window
		606
		607	;;;; TODO
		608
		609	jmp .trim_then_step6
		610
1249	hidnplayr	611	align 4
1514	hidnplayr	612	.LISTEN:
1196	hidnplayr	613
1514	hidnplayr	614	DEBUGF 1,"TCP state: listen\n"
1159	hidnplayr	615
1514	hidnplayr	616	test [edx + TCP_segment.Flags], TH_RST
		617	jnz .drop
1159	hidnplayr	618
1514	hidnplayr	619	test [edx + TCP_segment.Flags], TH_ACK
		620	jnz .drop_with_reset
1159	hidnplayr	621
1514	hidnplayr	622	test [edx + TCP_segment.Flags], TH_SYN
		623	jz .drop
1159	hidnplayr	624
1514	hidnplayr	625	; TODO: check if it's a broadcast or multicast, and drop if so
1159	hidnplayr	626
1514	hidnplayr	627	;;; 28.6
		628
		629	; create a new socket and fill in the nescessary variables
		630
		631	;; Exit if backlog queue is full
		632	; mov ax, [ebx + TCP_SOCKET.backlog_cur]
		633	; cmp ax, [ebx + TCP_SOCKET.backlog]
		634	; jae .exit
		635
		636	; Allocate new socket
		637	call SOCKET_alloc
		638	;;; jz .fail
		639
		640	; Copy structure from current socket to new, (including lock!)
		641	; We start at PID to reserve the socket num, and the 2 pointers at beginning of socket
		642	lea esi, [edx + SOCKET.PID]
		643	lea edi, [eax + SOCKET.PID]
		644	mov ecx, (TCP_SOCKET.end - SOCKET.PID + 3)/4
1274	hidnplayr	645	rep movsd
1159	hidnplayr	646
1514	hidnplayr	647	;; Push pointer to new socket to queue
		648	; movzx ecx, [ebx + TCP_SOCKET.backlog_cur]
		649	; inc [ebx + TCP_SOCKET.backlog_cur]
		650	; mov [ebx + TCP_SOCKET.end + ecx*4], eax
1159	hidnplayr	651
1514	hidnplayr	652	mov [eax + IP_SOCKET.RemoteIP], esi ; IP source address
1159	hidnplayr	653
1514	hidnplayr	654	mov cx, [edx + TCP_segment.SourcePort]
		655	mov [eax + TCP_SOCKET.RemotePort], cx
1159	hidnplayr	656
1514	hidnplayr	657	mov ecx, [edx + TCP_segment.SequenceNumber]
		658	mov [eax + TCP_SOCKET.IRS], ecx
1159	hidnplayr	659
1514	hidnplayr	660	mov ecx, [eax + TCP_SOCKET.ISS]
		661	mov [eax + TCP_SOCKET.SND_NXT], ecx
1159	hidnplayr	662
1514	hidnplayr	663	jmp .trim_then_step6
1159	hidnplayr	664
1254	hidnplayr	665
1159	hidnplayr	666
1514	hidnplayr	667	align 4
		668	.SYN_SENT:
1281	hidnplayr	669
1514	hidnplayr	670	DEBUGF 1,"TCP state: syn_sent\n"
1159	hidnplayr	671
1514	hidnplayr	672	test [edx + TCP_segment.Flags], TH_ACK
		673	jz @f
1281	hidnplayr	674
1514	hidnplayr	675	mov eax, [edx + TCP_segment.AckNumber]
		676	cmp eax, [ebx + TCP_SOCKET.ISS]
		677	jle .drop_with_reset
1281	hidnplayr	678
1514	hidnplayr	679	mov eax, [edx + TCP_segment.AckNumber]
		680	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		681	jg .drop_with_reset
		682	@@:
1281	hidnplayr	683
		684
1514	hidnplayr	685	test [edx + TCP_segment.Flags], TH_RST
		686	jz @f
1281	hidnplayr	687
1514	hidnplayr	688	test [edx + TCP_segment.Flags], TH_ACK
		689	jz .drop
1281	hidnplayr	690
1514	hidnplayr	691	;tp = tcp_drop(tp, ECONNREFUSED)
1159	hidnplayr	692
1514	hidnplayr	693	jmp .drop
		694	@@:
1159	hidnplayr	695
1514	hidnplayr	696	test [edx + TCP_segment.Flags], TH_SYN
		697	jz .drop
1318	hidnplayr	698
1514	hidnplayr	699	; now, process received SYN in response to an active open
		700	test [edx + TCP_segment.Flags], TH_ACK
		701	jz @f
		702
		703	mov eax, [edx + TCP_segment.AckNumber]
		704	mov [ebx + TCP_SOCKET.SND_UNA], eax
		705
		706	mov eax, [ebx + TCP_SOCKET.SND_UNA]
		707	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		708	jle @f
		709	mov [ebx + TCP_SOCKET.SND_NXT], eax
		710
1519	hidnplayr	711	mov [ebx + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval
		712	mov [ebx + TCP_SOCKET.timer_retransmission], 0
1514	hidnplayr	713
		714	mov eax, [edx + TCP_segment.SequenceNumber]
		715	mov [ebx + TCP_SOCKET.IRS], eax
		716
		717	; TODO: set socket state to connected
		718
		719	mov [ebx + TCP_SOCKET.t_state], TCB_ESTABLISHED
		720
		721	; TODO: check if we should scale the connection (567-572)
		722	; TODO: update RTT estimators
		723
		724
		725	@@:
		726
		727	; We have received a syn but no ACK, so we are having a simultaneous open..
		728	mov [ebx + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		729
		730	;-------------------------------------
		731	; Common processing for receipt of SYN
		732
		733	.trimthenstep6:
		734
		735	inc [edx + TCP_segment.SequenceNumber]
		736
		737	cmp cx, [ebx + TCP_SOCKET.RCV_WND]
		738	jle @f
		739
		740	movzx eax, cx
		741	sub ax, [ebx + TCP_SOCKET.RCV_WND]
		742	; TODO: 592
		743	mov cx, [ebx + TCP_SOCKET.RCV_WND]
		744	; TODO...
		745	@@:
		746	;;;;;
		747	;;; jmp .step6
		748
		749
		750
		751
		752
1274	hidnplayr	753	align 4
1514	hidnplayr	754	.trim_then_step6:
1159	hidnplayr	755
1514	hidnplayr	756	DEBUGF 1,"Trim, then step 6\n"
1159	hidnplayr	757
1514	hidnplayr	758	;----------------------------
		759	; trim any data not in window
1159	hidnplayr	760
1514	hidnplayr	761	mov eax, [ebx + TCP_SOCKET.RCV_NXT]
		762	sub eax, [edx + TCP_segment.SequenceNumber]
1318	hidnplayr	763
1514	hidnplayr	764	test eax, eax
		765	jz .no_drop
1274	hidnplayr	766
1514	hidnplayr	767	test [edx + TCP_segment.Flags], TH_SYN
		768	jz .no_drop
		769
		770	and [edx + TCP_segment.Flags], not (TH_SYN)
		771	inc [edx + TCP_segment.SequenceNumber]
		772
		773	cmp [edx + TCP_segment.UrgentPointer], 1
		774	jl @f
		775
		776	dec [edx + TCP_segment.UrgentPointer]
		777
		778	jmp .no_drop
		779	@@:
		780
		781	and [edx + TCP_segment.Flags], not (TH_URG)
		782	dec eax
		783
		784	.no_drop:
		785
		786	; eax holds number of bytes to drop
		787
		788
		789	;----------------------------------
		790	; Check for entire duplicate packet
		791
		792	cmp eax, ecx
		793	jge .duplicate
		794
		795	;;; TODO: figure 28.30
		796
		797	;; inc [TCP_segments_rx]
		798
		799	;; add dword [TCP_bytes_rx], ecx
		800	;; adc dword [TCP_bytes_rx+4], 0
		801
		802	;------------------------
		803	; Check for duplicate FIN
		804
		805	test [edx + TCP_segment.Flags], TH_FIN
		806	jz @f
		807	inc ecx
		808	cmp eax, ecx
		809	dec ecx
		810	jne @f
		811
		812	mov eax, ecx
		813	and [edx + TCP_segment.Flags], not TH_FIN
		814	;;; TODO: set ACKNOW flag
		815
		816	jmp .no_duplicate
		817	@@:
		818
		819	; Handle the case when a bound socket connects to itself
		820	; Allow packets with a SYN and an ACKto continue with the processing
		821
		822
		823	;-------------------------------------
		824	; Generate duplicate ACK if nescessary
		825
		826	; This code also handles simultaneous half-open or self-connects
		827
		828	test eax, eax
		829	jnz .drop_after_ack
		830
		831	cmp [edx + TCP_segment.Flags], TH_ACK
		832	jz .drop_after_ack
		833
		834	.duplicate:
		835
		836	;----------------------------------------
		837	; Update statistics for duplicate packets
		838
		839	;;; TODO
		840
		841	;;; DROP the packet ??
		842
		843	.no_duplicate:
		844
		845	;-----------------------------------------------
		846	; Remove duplicate data and update urgent offset
		847
		848	add [edx + TCP_segment.SequenceNumber], eax
		849
		850	;;; TODO
		851
		852	sub [edx + TCP_segment.UrgentPointer], ax
		853	jg @f
		854
		855	and [edx + TCP_segment.Flags], not (TH_URG)
		856	mov [edx + TCP_segment.UrgentPointer], 0
		857	@@:
		858
		859	;--------------------------------------------------
		860	; Handle data that arrives after process terminates
		861
		862	cmp [ebx + SOCKET.PID], 0
		863	jge @f
		864
		865	cmp [ebx + TCP_SOCKET.t_state], TCB_CLOSE_WAIT
		866	jle @f
		867
		868	test ecx, ecx
		869	jz @f
		870
		871	;;; Close the socket
		872	;;; update stats
		873
		874	jmp .drop_with_reset
		875
		876	@@:
		877
		878	;----------------------------------------
		879	; Remove data beyond right edge of window
		880
		881	mov eax, [edx + TCP_segment.SequenceNumber]
		882	add eax, ecx
		883	sub eax, [ebx + TCP_SOCKET.RCV_NXT]
		884	sub ax, [ebx + TCP_SOCKET.RCV_WND]
		885
		886	; eax now holds the number of bytes to drop
		887
		888	jle .no_excess_data
		889
		890	;;; TODO: update stats
		891
		892	cmp eax, ecx
		893	jl .dont_drop_all
		894
		895	;;; TODO 700-736
		896
		897	.dont_drop_all:
		898
		899	.no_excess_data:
		900
		901
		902	;-----------------
		903	; Record timestamp
		904
		905	;;; TODO 737-746
		906
		907	;------------------
		908	; Process RST flags
		909
		910	test [edx + TCP_segment.Flags], TH_RST
		911	jz .rst_skip
		912
		913	mov eax, [ebx + TCP_SOCKET.t_state]
		914	shl eax, 2
		915	jmp dword [eax + .rst_sw_list]
		916
		917	.rst_sw_list:
		918	dd .rst_skip ;TCB_CLOSED
		919	dd .rst_skip ;TCB_LISTEN
		920	dd .rst_skip ;TCB_SYN_SENT
		921	dd .econnrefused ;TCB_SYN_RECEIVED
		922	dd .econnreset ;TCB_ESTABLISHED
		923	dd .econnreset ;TCB_CLOSE_WAIT
		924	dd .econnreset ;TCB_FIN_WAIT_1
		925	dd .rst_close ;TCB_CLOSING
		926	dd .rst_close ;TCB_LAST_ACK
		927	dd .econnreset ;TCB_FIN_WAIT_2
		928	dd .rst_close ;TCB_TIMED_WAIT
		929
		930	.econnrefused:
		931
		932	;;; TODO: debug info
		933
		934	jmp .close
		935
		936	.econnreset:
		937
		938	;;; TODO: debug info
		939	.close:
		940
		941	;;; update stats
		942
		943	.rst_close:
		944
		945	;;; Close the socket
		946	jmp .drop
		947
		948	.rst_skip:
		949
		950	;--------------------------------------
		951	; handle SYN-full and ACK-less segments
		952
		953	test [edx + TCP_segment.Flags], TH_SYN
		954	jz @f
		955
		956	;;; tcp_drop ( ECONNRESET)
		957	jmp .drop_with_reset
		958
		959	test [edx + TCP_segment.Flags], TH_ACK
		960	jz .drop
		961
		962	;----------------
		963	; Process the ACK
		964
		965	cmp [ebx + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		966	jg .ack_dup
		967	jl .ack_nodup
		968
		969	;;;;;
		970
		971	.ack_dup:
		972
		973	;;;;
		974
		975	.ack_nodup:
		976
		977	;;;; 887
		978
		979	;-------------------------------------------------
1519	hidnplayr	980	; If the congestion window was inflated to account
1514	hidnplayr	981	; for the other side's cached packets, retrace it
		982
		983	;;;; 888 - 902
		984
		985
		986	;------------------------------------------
		987	; RTT measurements and retransmission timer
		988
		989	;;;;; 903 - 926
		990
1519	hidnplayr	991	mov [ebx + TCP_SOCKET.timer_retransmission], 0
1514	hidnplayr	992
1519	hidnplayr	993	mov eax, [ebx + TCP_SOCKET.SND_MAX]
		994	cmp eax, [edx + TCP_segment.AckNumber]
		995	je .all_outstanding
		996	mov [ebx + TCP_SOCKET.timer_retransmission], 120 ;;;; TODO: correct this value
		997	.all_outstanding:
		998
		999
1514	hidnplayr	1000	;-------------------------------------------
		1001	; Open congestion window in response to ACKs
		1002
		1003	;;;;
		1004
		1005
		1006	;------------------------------------------
		1007	; Remove acknowledged data from send buffer
		1008
		1009	;;;; 943 - 956
		1010
		1011	;---------------------------------------
		1012	; Wake up process waiting on send buffer
		1013
		1014	;;;;;
		1015
		1016	mov eax, [ebx + TCP_SOCKET.t_state]
		1017	shl eax, 2
		1018	jmp dword [eax + .ACK_sw_list]
		1019
		1020	.ACK_sw_list:
		1021	dd .step6 ;TCB_CLOSED
		1022	dd .step6 ;TCB_LISTEN
		1023	dd .step6 ;TCB_SYN_SENT
		1024	dd .step6 ;TCB_SYN_RECEIVED
		1025	dd .step6 ;TCB_ESTABLISHED
		1026	dd .step6 ;TCB_CLOSE_WAIT
		1027	dd ._963 ;TCB_FIN_WAIT_1
		1028	dd ._958 ;TCB_CLOSING
		1029	dd ._999 ;TCB_LAST_ACK
		1030	dd .step6 ;TCB_FIN_WAIT_2
		1031	dd ._1010 ;TCB_TIMED_WAIT
		1032
		1033
		1034	._963:
		1035
		1036
		1037	jmp .step6
		1038
		1039
		1040	._958:
		1041
		1042	jmp .step6
		1043
		1044	._999:
		1045
		1046	jmp .step6
		1047
		1048
		1049	._1010:
		1050
		1051	jmp .step6
		1052
		1053
		1054
		1055	align 4
		1056	.step6:
		1057
		1058	DEBUGF 1,"step 6\n"
		1059
		1060	;--------------------------
		1061	; update window information
		1062
		1063	test [edx + TCP_segment.Flags], TH_ACK
		1064	jz .no_window_update
		1065
		1066	mov eax, [ebx + TCP_SOCKET.SND_WL1]
		1067	cmp eax, [edx + TCP_segment.SequenceNumber]
		1068
		1069	;;;; 1021
		1070
		1071	;----------------------------------
		1072	; Keep track of pure window updates
		1073
		1074	test ecx, ecx
		1075	jz @f
		1076
		1077	mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1078	cmp eax, [edx + TCP_segment.AckNumber]
		1079	jne @f
		1080
		1081	;; mov eax, tiwin
		1082	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		1083	jle @f
		1084
		1085	;;; update stats
		1086
		1087	@@:
		1088
		1089	;; mov eax, incoming window
		1090	cmp eax, [ebx + TCP_SOCKET.max_sndwnd]
		1091	jle @f
		1092	mov [ebx + TCP_SOCKET.max_sndwnd], eax
		1093	@@:
		1094	mov [ebx + TCP_SOCKET.SND_WND], eax
		1095
		1096	mov eax, [edx + TCP_segment.SequenceNumber]
		1097	mov [ebx + TCP_SOCKET.SND_WL1], eax
		1098
		1099	mov eax, [edx + TCP_segment.AckNumber]
		1100	mov [ebx + TCP_SOCKET.SND_WL2], eax
		1101
		1102	;;; needoutput = 1
		1103
		1104	.no_window_update:
		1105
		1106
		1107	;-----------------
		1108	; process URG flag
		1109
		1110	test [edx + TCP_segment.Flags], TH_URG
		1111	jz .not_urgent
		1112
		1113	cmp [edx + TCP_segment.UrgentPointer], 0
		1114	jz .not_urgent
		1115
		1116	cmp [ebx + TCP_SOCKET.t_state], TCB_TIMED_WAIT
		1117	je .not_urgent
		1118
		1119	; Ignore bogus urgent offsets
		1120
		1121	;;; 1040-1050
		1122
		1123	movzx eax, [edx + TCP_segment.UrgentPointer]
		1124	add eax, [ebx + SOCKET.SO_RCV.SB_CC]
		1125	cmp eax, SOCKET_MAXDATA
		1126	jle .not_urgent
		1127
		1128	mov [edx + TCP_segment.UrgentPointer], 0
		1129	and [edx + TCP_segment.Flags], not (TH_URG)
		1130	jmp .do_data
		1131
		1132	.not_urgent:
		1133
		1134	;--------------------------------------
		1135	; processing of received urgent pointer
		1136
		1137	;;; 1051-1093
		1138
		1139	align 4
		1140	.do_data:
		1141
		1142	DEBUGF 1,"Do data:\n"
		1143
		1144	; process the data in the segment
		1145
		1146	test [edx + TCP_segment.Flags], TH_FIN
		1147	jz .process_fin
		1148
		1149	test [ebx + TCP_SOCKET.t_state], TCB_FIN_WAIT_1 ;;;;;
		1150	jge .dont_do_data
		1151
		1152	DEBUGF 1,"Processing data in segment\n"
		1153
		1154	;;; NOW, process the data
		1155
		1156	jmp .final_processing
		1157
		1158
		1159	.dont_do_data:
		1160
		1161
		1162	;---------------
		1163	; FIN processing
		1164
		1165	.process_fin:
		1166
		1167	DEBUGF 1,"Processing FIN\n"
		1168
		1169	mov eax, [ebx + TCP_SOCKET.t_state]
		1170	shl eax, 2
		1171	jmp dword [eax + .FIN_sw_list]
		1172
		1173	.FIN_sw_list:
		1174	dd .no_fin ;TCB_CLOSED
		1175	dd .no_fin ;TCB_LISTEN
		1176	dd .no_fin ;TCB_SYN_SENT
		1177	dd ._1131 ;TCB_SYN_RECEIVED
		1178	dd ._1131 ;TCB_ESTABLISHED
		1179	dd .no_fin ;TCB_CLOSE_WAIT
		1180	dd ._1139 ;TCB_FIN_WAIT_1
		1181	dd .no_fin ;TCB_CLOSING
		1182	dd .no_fin ;TCB_LAST_ACK
		1183	dd ._1147 ;TCB_FIN_WAIT_2
		1184	dd ._1156 ;TCB_TIMED_WAIT
		1185
		1186
		1187
		1188	._1131:
		1189
		1190	._1139:
		1191
		1192	._1147:
		1193
		1194	._1156:
		1195
		1196
		1197	.no_fin:
		1198
		1199	;-----------------
		1200	; Final processing
		1201
		1202	.final_processing:
		1203
		1204	DEBUGF 1,"Final processing\n"
		1205
		1206	;;; if debug enabled, output packet
		1207
		1208	;test ;;;needoutput = 1
		1209	;jnz .outputnow
		1210
		1211	test [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
		1212	jz .ret
		1213
		1214	.outputnow:
		1215	call TCP_output
		1216
		1217	.ret:
		1218	mov [ebx + SOCKET.lock], 0
		1219
1274	hidnplayr	1220	call kernel_free
1514	hidnplayr	1221	ret 4
1274	hidnplayr	1222
1514	hidnplayr	1223	;------------------------------------------
		1224	; Generate an ACK, droping incoming segment
1274	hidnplayr	1225
1514	hidnplayr	1226	align 4
		1227	.drop_after_ack:
1274	hidnplayr	1228
1514	hidnplayr	1229	DEBUGF 1,"Drop after ACK\n"
1274	hidnplayr	1230
1514	hidnplayr	1231	test [edx + TCP_segment.Flags], TH_RST
		1232	jnz .drop
1274	hidnplayr	1233
1514	hidnplayr	1234	and [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1274	hidnplayr	1235
1514	hidnplayr	1236	call TCP_output
1318	hidnplayr	1237
1514	hidnplayr	1238	mov [ebx + SOCKET.lock], 0
1274	hidnplayr	1239
1514	hidnplayr	1240	call kernel_free
		1241	ret 4
1274	hidnplayr	1242
1514	hidnplayr	1243
		1244	;-------------------------------------------
		1245	; Generate an RST, dropping incoming segment
		1246
		1247	align 4
		1248	.drop_with_reset:
		1249
		1250	DEBUGF 1,"Drop with reset\n"
		1251
		1252	test [edx + TCP_segment.Flags], TH_RST
		1253	jnz .drop
		1254
		1255	;;; if its a multicast/broadcast, also drop
		1256
		1257	test [edx + TCP_segment.Flags], TH_ACK
		1258	jnz .respond_ack
		1259
		1260	test [edx + TCP_segment.Flags], TH_SYN
		1261	jnz .respond_syn
		1262
		1263	mov [ebx + SOCKET.lock], 0
		1264
		1265	call kernel_free
		1266	ret 4
		1267
		1268	.respond_ack:
		1269
		1270	;;;;
		1271
		1272	call TCP_respond
		1273
		1274	jmp .destroy_new_socket
		1275
		1276
		1277	.respond_syn:
		1278
		1279	;;;;
		1280
		1281	call TCP_respond
		1282
		1283	jmp .destroy_new_socket
		1284
		1285	;-----
		1286	; Drop
		1287
		1288	align 4
		1289	.drop:
		1290
		1291	DEBUGF 1,"Dropping packet\n"
		1292
		1293	;;;; If debugging options are enabled, output the packet somwhere
		1294
		1295	.destroy_new_socket:
		1296
		1297	;;;; kill the newly created socket
		1298
		1299	mov [ebx + SOCKET.lock], 0
		1300
		1301	call kernel_free
		1302	ret 4
		1303
		1304
		1305
		1306	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
		1307
		1308
		1309
		1310	;---------------------
1318	hidnplayr	1311	;
1514	hidnplayr	1312	; TCP_do_options
1318	hidnplayr	1313	;
1514	hidnplayr	1314	;-------------------
		1315
1318	hidnplayr	1316	align 4
1514	hidnplayr	1317	TCP_do_options:
1274	hidnplayr	1318
1514	hidnplayr	1319	DEBUGF 1,"TCP_do_options\n"
1274	hidnplayr	1320
1514	hidnplayr	1321	push eax
		1322	sub eax, 20
		1323	jz .no_options
1274	hidnplayr	1324
1514	hidnplayr	1325	lea esi, [edx + TCP_segment.Data]
1318	hidnplayr	1326
1514	hidnplayr	1327
		1328	;-------------------------------------------
		1329	; Begin the loop by checking for EOL and NOP
		1330
1318	hidnplayr	1331	.loop:
		1332
1514	hidnplayr	1333	cmp byte [esi], TCP_OPT_EOL ; end of option list?
		1334	jz .no_options
1318	hidnplayr	1335
1514	hidnplayr	1336	cmp byte [esi], TCP_OPT_NOP ; nop ?
		1337	;;; cmove edi, 1 ; if so, set option size to 1
		1338	jz .continue ; and continue scanning
1318	hidnplayr	1339
1514	hidnplayr	1340	;------------------
		1341	; We have an option
1318	hidnplayr	1342
1514	hidnplayr	1343	movzx edi, byte [esi + 1] ; get the length of this option in edi
1318	hidnplayr	1344
		1345
1514	hidnplayr	1346	;--------------------------------------
		1347	; Check for Maximum segment size option
1318	hidnplayr	1348
1514	hidnplayr	1349	cmp byte [esi], TCP_OPT_MAXSEG
		1350	jne .no_maxseg
1318	hidnplayr	1351
1514	hidnplayr	1352	cmp edi, 4 ; option length
		1353	jne .continue
1318	hidnplayr	1354
1514	hidnplayr	1355	test [edx + TCP_segment.Flags], TH_SYN
		1356	jz .continue
1318	hidnplayr	1357
1514	hidnplayr	1358	; Now parse the option...
1318	hidnplayr	1359
1514	hidnplayr	1360	jmp .continue
1318	hidnplayr	1361
1514	hidnplayr	1362	.no_maxseg:
1318	hidnplayr	1363
1514	hidnplayr	1364	;------------------------
		1365	; Check for Window option
1318	hidnplayr	1366
1514	hidnplayr	1367	cmp byte [esi], TCP_OPT_WINDOW
		1368	jne .no_window
1318	hidnplayr	1369
1514	hidnplayr	1370	cmp edi, 3 ; option length
		1371	jne .continue
1318	hidnplayr	1372
1514	hidnplayr	1373	test [edx + TCP_segment.Flags], TH_SYN
		1374	jz .continue
1318	hidnplayr	1375
1514	hidnplayr	1376	; ...
1318	hidnplayr	1377
1514	hidnplayr	1378	jmp .continue
1318	hidnplayr	1379
1514	hidnplayr	1380	.no_window:
1318	hidnplayr	1381
1514	hidnplayr	1382	;---------------------------
		1383	; Check for Timestamp option
1318	hidnplayr	1384
1514	hidnplayr	1385	cmp byte [esi], TCP_OPT_TIMESTAMP
		1386	jne .no_timestamp
1318	hidnplayr	1387
1514	hidnplayr	1388	cmp edi, 10 ; option length
		1389	jne .continue
1318	hidnplayr	1390
1514	hidnplayr	1391	; ...
		1392
		1393
		1394	jmp .continue
		1395
		1396	.no_timestamp:
		1397
		1398	;----------------------------------
		1399	; Future options may be placed here
		1400
		1401
		1402
		1403
		1404	;------------------------------
		1405	; Continue scanning for options
		1406
		1407	.continue:
		1408	add esi, edi
		1409	sub eax, edi
		1410	jg .loop
		1411
		1412	.no_options:
		1413
1318	hidnplayr	1414	pop eax
1514	hidnplayr	1415
1318	hidnplayr	1416	ret
		1417
1514	hidnplayr	1418
		1419
		1420
		1421	;---------------------------
		1422	;
		1423	; TCP_pull_out_of_band
		1424	;
		1425	; IN: eax =
		1426	; ebx = socket ptr
		1427	; edx = tcp packet ptr
		1428	;
		1429	; OUT: /
		1430	;
		1431	;---------------------------
		1432
		1433	align 4
		1434	TCP_pull_out_of_band:
		1435
		1436	DEBUGF 1,"TCP_pull_out_of_band\n"
		1437
		1438	;;;; 1282-1305
		1439
1318	hidnplayr	1440	ret
		1441
		1442
		1443
		1444
1514	hidnplayr	1445
		1446	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
		1447
		1448
		1449
		1450
		1451
1318	hidnplayr	1452	;-----------------------------------------------------------------
		1453	;
1514	hidnplayr	1454	; TCP_output
1318	hidnplayr	1455	;
1519	hidnplayr	1456	; IN: eax = socket pointer
1514	hidnplayr	1457	;; esi = ptr to data
		1458	;; ecx = number of data bytes
		1459	;
1318	hidnplayr	1460	; OUT: /
		1461	;
		1462	;-----------------------------------------------------------------
		1463	align 4
1514	hidnplayr	1464	TCP_output:
1318	hidnplayr	1465
1514	hidnplayr	1466	DEBUGF 1,"TCP_output, socket: %x\n", eax
1318	hidnplayr	1467
1514	hidnplayr	1468	; We'll detect the length of the data to be transmitted, and flags to be used
		1469	; If there is some data, or any critical controls to send (SYN / RST), then transmit
		1470	; Otherwise, investigate further
1318	hidnplayr	1471
1514	hidnplayr	1472	mov ebx, [eax + TCP_SOCKET.SND_MAX]
		1473	cmp ebx, [eax + TCP_SOCKET.SND_UNA]
		1474	jne .not_idle
1318	hidnplayr	1475
1514	hidnplayr	1476	mov ebx, [eax + TCP_SOCKET.t_idle]
		1477	cmp ebx, [eax + TCP_SOCKET.t_rxtcur]
		1478	jle .not_idle
1318	hidnplayr	1479
1514	hidnplayr	1480	; We have been idle for a while and no ACKS are expected to clock out any data we send..
		1481	; Slow start to get ack "clock" running again.
1318	hidnplayr	1482
1514	hidnplayr	1483	mov ebx, [eax + TCP_SOCKET.t_maxseg]
		1484	mov [eax + TCP_SOCKET.SND_CWND], ebx
1318	hidnplayr	1485
1514	hidnplayr	1486	.not_idle:
		1487	.again:
		1488	mov ebx, [eax + TCP_SOCKET.SND_NXT] ; calculate offset
		1489	sub ebx, [eax + TCP_SOCKET.SND_UNA] ;
1318	hidnplayr	1490
1514	hidnplayr	1491	mov ecx, [eax + TCP_SOCKET.SND_WND] ; determine window
		1492	cmp ecx, [eax + TCP_SOCKET.SND_CWND] ;
		1493	jl @f ;
		1494	mov ecx, [eax + TCP_SOCKET.SND_CWND] ;
		1495	@@: ;
1318	hidnplayr	1496
1514	hidnplayr	1497	call TCP_outflags
1318	hidnplayr	1498
1514	hidnplayr	1499	; If in persist timeout with window of 0, send 1 byte.
		1500	; Otherwise, if window is small but nonzero, and timer expired,
		1501	; we will send what we can and go to transmit state
1318	hidnplayr	1502
1514	hidnplayr	1503	test [eax + TCP_SOCKET.t_force], -1
		1504	jz .no_persist_timeout
1318	hidnplayr	1505
1514	hidnplayr	1506	test ecx, ecx
		1507	jnz .no_zero_window
1255	hidnplayr	1508
1514	hidnplayr	1509	cmp ebx, [eax + SOCKET.SO_SND.SB_CC]
		1510	jge @f
1255	hidnplayr	1511
1514	hidnplayr	1512	and dl, not (TH_FIN) ; clear the FIN flag ??? how can it be set before?
1255	hidnplayr	1513
1514	hidnplayr	1514	@@:
		1515	inc ecx
		1516	jmp .no_persist_timeout
1255	hidnplayr	1517
1514	hidnplayr	1518	.no_zero_window:
1254	hidnplayr	1519
1514	hidnplayr	1520	;;; mov [eax + TCP_SOCKET.t_timer....TCPT_PERSIST], 0
		1521	mov [eax + TCP_SOCKET.t_rxtshift], 0
1254	hidnplayr	1522
1514	hidnplayr	1523	.no_persist_timeout:
1159	hidnplayr	1524
1514	hidnplayr	1525	;;;106
1159	hidnplayr	1526
1514	hidnplayr	1527	mov esi, [eax + SOCKET.SO_SND.SB_CC]
		1528	cmp esi, ecx
		1529	jl @f
		1530	mov esi, ecx
		1531	@@:
		1532	sub esi, ebx
1254	hidnplayr	1533
1514	hidnplayr	1534	cmp esi, -1
		1535	jne .not_minus_one
1159	hidnplayr	1536
1514	hidnplayr	1537	; If FIN has been set, but not ACKed, and we havent been called to retransmit,
		1538	; len (esi) will be -1
		1539	; Otherwise, window shrank after we sent into it.
		1540	; If window shrank to 0, cancel pending retransmit and pull SND_NXT back to (closed) window
		1541	; We will enter persist state below.
		1542	; If window didn't close completely, just wait for an ACK
1159	hidnplayr	1543
1514	hidnplayr	1544	xor esi, esi
1159	hidnplayr	1545
1514	hidnplayr	1546	test ecx, ecx
		1547	jnz @f
1159	hidnplayr	1548
1514	hidnplayr	1549	;;; mov [eax + TCP_SOCKET.t_timer..TCPT_REXMT], 0
1274	hidnplayr	1550
1514	hidnplayr	1551	push [eax + TCP_SOCKET.SND_UNA]
		1552	pop [eax + TCP_SOCKET.SND_NXT]
		1553	@@:
1254	hidnplayr	1554
1514	hidnplayr	1555	.not_minus_one:
1254	hidnplayr	1556
1514	hidnplayr	1557	;;; 124
1159	hidnplayr	1558
1514	hidnplayr	1559	cmp esi, [eax + TCP_SOCKET.t_maxseg]
		1560	jle @f
1274	hidnplayr	1561
1514	hidnplayr	1562	mov esi, [eax + TCP_SOCKET.t_maxseg]
		1563	;sendalot = 1
1274	hidnplayr	1564
1514	hidnplayr	1565	@@:
1274	hidnplayr	1566
1514	hidnplayr	1567	;;; 128
1274	hidnplayr	1568
1514	hidnplayr	1569	mov edi, [eax + TCP_SOCKET.SND_NXT]
		1570	add edi, esi ; len
		1571	sub edi, [eax + TCP_SOCKET.SND_UNA]
		1572	add edi, [eax + SOCKET.SO_SND.SB_CC]
		1573	cmp edi, 0
		1574	jle @f
1274	hidnplayr	1575
1514	hidnplayr	1576	and dl, not (TH_FIN) ; clear the FIN flag
1159	hidnplayr	1577
1514	hidnplayr	1578	@@:
1159	hidnplayr	1579
		1580
1514	hidnplayr	1581	;;;; 130 TODO: set window (ecx) to space in send buffer
1159	hidnplayr	1582
		1583
1514	hidnplayr	1584	;------------------------------
		1585	; Sender silly window avoidance
1159	hidnplayr	1586
1514	hidnplayr	1587	test esi, esi
		1588	jz .zero_length
1159	hidnplayr	1589
1249	hidnplayr	1590
1514	hidnplayr	1591	cmp esi, [eax + TCP_SOCKET.t_maxseg]
		1592	je .send
1274	hidnplayr	1593
1514	hidnplayr	1594	;;; TODO: 144-145
1274	hidnplayr	1595
1514	hidnplayr	1596	test [eax + TCP_SOCKET.t_force], -1
		1597	jnz .send
1274	hidnplayr	1598
1514	hidnplayr	1599	;;; TODO: 149..152
1274	hidnplayr	1600
1514	hidnplayr	1601	.zero_length:
1254	hidnplayr	1602
		1603
1514	hidnplayr	1604	;----------------------------------------
		1605	; Check if a window update should be sent
1159	hidnplayr	1606
1514	hidnplayr	1607	cmp ecx, 0 ; window
		1608	jle .no_window
1159	hidnplayr	1609
1514	hidnplayr	1610	;;; TODO 154-172
1159	hidnplayr	1611
1514	hidnplayr	1612	.no_window:
1159	hidnplayr	1613
1514	hidnplayr	1614	;--------------------------
		1615	; Should a segment be sent?
1159	hidnplayr	1616
1514	hidnplayr	1617	test [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
		1618	jnz .send
1159	hidnplayr	1619
1514	hidnplayr	1620	test dl, TH_SYN + TH_RST
		1621	jnz .send
1159	hidnplayr	1622
1514	hidnplayr	1623	mov eax, [ebx + TCP_SOCKET.SND_UP]
		1624	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
		1625	jg .send
1249	hidnplayr	1626
1514	hidnplayr	1627	test dl, TH_FIN
		1628	jz .enter_persist
1318	hidnplayr	1629
1514	hidnplayr	1630	test [ebx + TCP_SOCKET.t_flags], TF_SENTFIN
		1631	jnz .send
1254	hidnplayr	1632
1514	hidnplayr	1633	mov eax, [ebx + TCP_SOCKET.SND_NXT]
		1634	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
		1635	je .send
1254	hidnplayr	1636
1514	hidnplayr	1637	;--------------------
		1638	; Enter persist state
1318	hidnplayr	1639
1514	hidnplayr	1640	.enter_persist:
1318	hidnplayr	1641
1519	hidnplayr	1642	DEBUGF 1,"Entering persist state\n"
1318	hidnplayr	1643
		1644
		1645
1514	hidnplayr	1646	;--------------------------------------
		1647	; No reason to send a segment, just ret
1318	hidnplayr	1648
1514	hidnplayr	1649	DEBUGF 1,"No reason to send a segment\n"
1318	hidnplayr	1650
1514	hidnplayr	1651	ret
1318	hidnplayr	1652
		1653
		1654
		1655
		1656
1514	hidnplayr	1657	;-----------------------------------------------
		1658	;
		1659	; Send a segment
		1660	;
		1661	; ebx = socket pointer
		1662	; dl = flags
		1663	;
		1664	;-----------------------------------------------
1318	hidnplayr	1665
1514	hidnplayr	1666	.send:
1318	hidnplayr	1667
1514	hidnplayr	1668	DEBUGF 1,"Preparing to send a segment\n"
1318	hidnplayr	1669
1514	hidnplayr	1670	xor edi, edi ; edi will contain the number of header option bytes
1318	hidnplayr	1671
1514	hidnplayr	1672	;------------------------------------
		1673	; Send options with first SYN segment
1318	hidnplayr	1674
1514	hidnplayr	1675	test dl, TH_SYN
		1676	jz .no_options
1318	hidnplayr	1677
1514	hidnplayr	1678	mov eax, [ebx + TCP_SOCKET.ISS]
		1679	mov [ebx + TCP_SOCKET.SND_NXT], eax
1318	hidnplayr	1680
1514	hidnplayr	1681	test [ebx + TCP_SOCKET.t_flags], TF_NOOPT
		1682	jnz .no_options
1318	hidnplayr	1683
1514	hidnplayr	1684	mov eax, TCP_OPT_MAXSEG shl 24 + 4 shl 16
		1685	mov ax, 1280 ;;;;;;
1318	hidnplayr	1686	bswap eax
1514	hidnplayr	1687	push eax
		1688
		1689	mov di, 4
		1690
		1691	test [ebx + TCP_SOCKET.t_flags], TF_REQ_SCALE
		1692	jz .no_syn
		1693
		1694	test dl, TH_ACK
		1695	jnz .scale_opt
		1696
		1697	test [ebx + TCP_SOCKET.t_flags], TF_RCVD_SCALE
		1698	jz .no_syn
		1699
		1700	.scale_opt:
		1701
		1702	mov eax, TCP_OPT_WINDOW shl 24 + 4 shl 16 + TCP_OPT_NOP
		1703	mov ah, byte [ebx + TCP_SOCKET.request_r_scale]
1318	hidnplayr	1704	bswap eax
1514	hidnplayr	1705	push eax
1255	hidnplayr	1706
1514	hidnplayr	1707	add di, 4
1159	hidnplayr	1708
1514	hidnplayr	1709	.no_syn:
1159	hidnplayr	1710
1514	hidnplayr	1711	;------------------------------------
		1712	; Make the timestamp option if needed
1159	hidnplayr	1713
1514	hidnplayr	1714	test [ebx + TCP_SOCKET.t_flags], TF_REQ_TSTMP
		1715	jz .no_timestamp
1159	hidnplayr	1716
1514	hidnplayr	1717	test dl, TH_RST
		1718	jnz .no_timestamp
		1719
		1720	test dl, TH_ACK
		1721	jz .timestamp
		1722
		1723	test [ebx + TCP_SOCKET.t_flags], TF_RCVD_TSTMP
		1724	jz .no_timestamp
		1725
		1726	.timestamp:
		1727
		1728	DEBUGF 1,"Creating a timestamp\n"
		1729
		1730	push dword (TCP_OPT_TIMESTAMP shl 8 + 10 + TCP_OPT_NOP shl 16 + TCP_OPT_NOP shl 24)
		1731	pushw 0
		1732	mov eax, [timer_ticks]
		1733	bswap eax
		1734	push eax
		1735
		1736	add di, 10
		1737
		1738	.no_timestamp:
		1739
		1740	;; TODO: check if we dont exceed the max segment size
		1741
		1742	.no_options:
		1743	add edi, TCP_segment.Data
		1744
		1745	;-----------------------------------
		1746	; Check if we have some data to send
		1747
		1748	;;; mov ecx, [huppeldepup]
		1749
1255	hidnplayr	1750	test ecx, ecx
1514	hidnplayr	1751	jz .no_data
1159	hidnplayr	1752
1514	hidnplayr	1753	;;; 278-316
1281	hidnplayr	1754
1514	hidnplayr	1755	jmp .header
1281	hidnplayr	1756
1514	hidnplayr	1757	.no_data:
1159	hidnplayr	1758
1514	hidnplayr	1759	;;; 317-338
1281	hidnplayr	1760
		1761
1514	hidnplayr	1762	;----------
		1763
		1764	push di dx ebx
		1765
		1766	add ecx, edi ; total TCP segment size
		1767
		1768	mov eax, [ebx + IP_SOCKET.RemoteIP]
		1769	mov ebx, [ebx + IP_SOCKET.LocalIP]
		1770	mov di , IP_PROTO_TCP
		1771	call IPv4_create_packet
		1772
		1773	;;;; jz .fail
		1774
		1775	push edx eax
1519	hidnplayr	1776	call [ebx + NET_DEVICE.transmit]
1159	hidnplayr	1777	ret
		1778
1514	hidnplayr	1779	;----------------
1159	hidnplayr	1780
1249	hidnplayr	1781
1514	hidnplayr	1782	;-------------------------------
		1783	; Now, create the 20-byte header
1274	hidnplayr	1784
1514	hidnplayr	1785	.header:
1274	hidnplayr	1786
1514	hidnplayr	1787	;-----------------------
		1788	; Fill in the TCP header
		1789	pop esi
1274	hidnplayr	1790
1514	hidnplayr	1791	push [esi + TCP_SOCKET.SND_NXT]
		1792	rol word [esp], 8
		1793	rol dword [esp], 16
		1794	pop [edi + TCP_segment.SequenceNumber]
1274	hidnplayr	1795
1514	hidnplayr	1796	push [esi + TCP_SOCKET.RCV_NXT]
		1797	rol word [esp], 8
		1798	rol dword [esp], 16
		1799	pop [edi + TCP_segment.AckNumber]
1274	hidnplayr	1800
1514	hidnplayr	1801	push [esi + TCP_SOCKET.LocalPort]
		1802	rol word [esp], 8
		1803	pop [edi + TCP_segment.SourcePort]
1274	hidnplayr	1804
1514	hidnplayr	1805	push [esi + TCP_SOCKET.RemotePort]
		1806	rol word [esp], 8
		1807	pop [edi + TCP_segment.DestinationPort]
1254	hidnplayr	1808
		1809
1514	hidnplayr	1810	mov [edi + TCP_segment.Window], 0x0005
		1811	; 1280 bytes
		1812	mov [edi + TCP_segment.UrgentPointer], 0
1159	hidnplayr	1813
1514	hidnplayr	1814	mov [edi + TCP_segment.DataOffset], 0x50
1159	hidnplayr	1815
1514	hidnplayr	1816	mov [edi + TCP_segment.Flags], cl
1159	hidnplayr	1817
1514	hidnplayr	1818	mov [edi + TCP_segment.Checksum], 0
1159	hidnplayr	1819
1514	hidnplayr	1820	;-----
1159	hidnplayr	1821
		1822
1514	hidnplayr	1823	;--------------
		1824	; Copy the data
1159	hidnplayr	1825
1514	hidnplayr	1826	pop esi
		1827	push edi
		1828	add edi, TCP_segment.Data ;;
		1829	sub ecx, TCP_segment.Data ;;;
1249	hidnplayr	1830
1514	hidnplayr	1831	shr ecx, 1
		1832	jnc .nb
		1833	movsb
		1834	.nb:
		1835	shr ecx, 1
		1836	jnc .nw
		1837	movsw
		1838	.nw:
		1839	test ecx, ecx
		1840	jz .nd
		1841	rep movsd
		1842	.nd:
		1843	pop edi
1254	hidnplayr	1844
1514	hidnplayr	1845	;--------------------
		1846	; Create the checksum
1254	hidnplayr	1847
1514	hidnplayr	1848	push [ebx + IP_SOCKET.LocalIP]
		1849	push [ebx + IP_SOCKET.RemoteIP]
		1850	call TCP_checksum
1159	hidnplayr	1851
1514	hidnplayr	1852	;----------------
		1853	; Send the packet
1159	hidnplayr	1854
1514	hidnplayr	1855	;;;;;
1159	hidnplayr	1856
1514	hidnplayr	1857
		1858	DEBUGF 1,"Sending TCP Packet to device %x\n", ebx
1519	hidnplayr	1859	call [ebx + NET_DEVICE.transmit]
1159	hidnplayr	1860	ret
		1861
1514	hidnplayr	1862	;-------------------------
		1863	;
		1864	; TCP_outflags
		1865	;
		1866	; IN: eax = socket ptr
		1867	;
		1868	; OUT: edx = flags
		1869	;
		1870	;-------------------------
1249	hidnplayr	1871	align 4
1514	hidnplayr	1872	TCP_outflags:
1254	hidnplayr	1873
1514	hidnplayr	1874	mov edx, [eax + TCP_SOCKET.t_state]
		1875	movzx edx, byte [edx + .flaglist]
1254	hidnplayr	1876
1514	hidnplayr	1877	DEBUGF 1,"TCP_outflags, socket: %x, flags: %x\n", eax, dl
		1878
1159	hidnplayr	1879	ret
		1880
1514	hidnplayr	1881	.flaglist:
1159	hidnplayr	1882
1514	hidnplayr	1883	db TH_RST + TH_ACK ; TCB_CLOSED
		1884	db 0 ; TCB_LISTEN
		1885	db TH_SYN ; TCB_SYN_SENT
		1886	db TH_SYN + TH_ACK ; TCB_SYN_RECEIVED
		1887	db TH_ACK ; TCB_ESTABLISHED
		1888	db TH_ACK ; TCB_CLOSE_WAIT
		1889	db TH_SYN + TH_ACK ; TCB_FIN_WAIT_1
		1890	db TH_SYN + TH_ACK ; TCB_CLOSING
		1891	db TH_SYN + TH_ACK ; TCB_LAST_ACK
		1892	db TH_ACK ; TCB_FIN_WAIT_2
		1893	db TH_ACK ; TCB_TIMED_WAIT
1249	hidnplayr	1894
1514	hidnplayr	1895
		1896	;-------------------------
		1897	;
		1898	; TCP_drop
		1899	;
		1900	; IN: eax = socket ptr
		1901	;
		1902	; OUT: /
		1903	;
		1904	;-------------------------
1249	hidnplayr	1905	align 4
1514	hidnplayr	1906	TCP_drop:
1254	hidnplayr	1907
1514	hidnplayr	1908	DEBUGF 1,"TCP_drop\n"
1254	hidnplayr	1909
1514	hidnplayr	1910	; cmp [eax + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		1911	; jl .no_syn_received
1159	hidnplayr	1912
1514	hidnplayr	1913	mov [eax + TCP_SOCKET.t_state], TCB_CLOSED
1159	hidnplayr	1914
1514	hidnplayr	1915	call TCP_output
1254	hidnplayr	1916
1514	hidnplayr	1917	; .no_syn_received:
		1918
1159	hidnplayr	1919	ret
		1920
		1921
1254	hidnplayr	1922
		1923
1159	hidnplayr	1924
1514	hidnplayr	1925	;---------------------------------------
		1926	;
1519	hidnplayr	1927	; TCP_ack
1514	hidnplayr	1928	;
1519	hidnplayr	1929	; The easy way to send an ACK/RST/keepalive segment
1514	hidnplayr	1930	;
		1931	; IN: eax = socket ptr
1519	hidnplayr	1932	; -or-
		1933	; edx = packet ptr (eax must be 0)
		1934	; cl = flags
1514	hidnplayr	1935	;
		1936	; OUT: /
		1937	;
		1938	;---------------------------------------
		1939	align 4
		1940	TCP_respond:
1254	hidnplayr	1941
1514	hidnplayr	1942	DEBUGF 1,"TCP_respond\n"
1159	hidnplayr	1943
1519	hidnplayr	1944	;---------------------
		1945	; Create the IP packet
		1946
		1947	push cx eax edx
		1948	mov ebx, [eax + IP_SOCKET.LocalIP]
		1949	mov eax, [eax + IP_SOCKET.RemoteIP]
		1950	mov ecx, TCP_segment.Data
		1951	mov di , IP_PROTO_TCP
		1952	call IPv4_create_packet
		1953	test edi, edi
		1954	jz .error
		1955
		1956	;---------------------------
		1957	; Now fill in the TCP header
		1958
		1959	pop ecx
		1960	pop esi
		1961
		1962	test esi, esi
		1963	; jz
		1964
		1965
		1966	push edx eax
		1967
		1968	push dword .checksum
		1969	je .use_segment
		1970	jmp .use_socket
		1971
		1972	;---------------------
		1973	; Fill in the checksum
		1974
		1975	.checksum:
		1976
		1977	push [esi + IP_SOCKET.LocalIP]
		1978	push [esi + IP_SOCKET.RemoteIP]
		1979	lea esi, [edi - 20]
		1980	xor ecx, ecx
		1981	call TCP_checksum
		1982
		1983	;--------------------
		1984	; And send the segment
		1985
		1986	call [ebx + NET_DEVICE.transmit]
1159	hidnplayr	1987	ret
		1988
1519	hidnplayr	1989	.error:
		1990	DEBUGF 1,"TCP_ack failed\n"
		1991	add esp, 4
1159	hidnplayr	1992
1519	hidnplayr	1993	ret
1514	hidnplayr	1994
1519	hidnplayr	1995	;---------------------------------------------------
		1996	; Fill in the TCP header by using a received segment
		1997
		1998	.use_segment:
		1999
		2000	mov ax, [esi + TCP_segment.DestinationPort]
		2001	rol ax, 8
		2002	stosw
		2003	mov ax, [esi + TCP_segment.SourcePort]
		2004	rol ax, 8
		2005	stosw
		2006	mov eax, [esi + TCP_segment.AckNumber]
		2007	bswap eax
		2008	stosd
		2009	xor eax, eax
		2010	stosd
		2011	mov al, 0x50 ; Dataoffset: 20 bytes
		2012	stosb
		2013	mov al, cl
		2014	stosb
		2015	mov ax, 1280
		2016	rol ax, 8
		2017	stosw ; window
		2018	xor eax, eax
		2019	stosd ; checksum + urgentpointer
		2020
		2021	ret
		2022
		2023
		2024	;-----------------------------------------------
		2025	; Fill in the TCP header by using the socket ptr
		2026
		2027	.use_socket:
		2028
		2029	mov ax, [esi + TCP_SOCKET.LocalPort]
		2030	rol ax, 8
		2031	stosw
		2032	mov ax, [esi + TCP_SOCKET.RemotePort]
		2033	rol ax, 8
		2034	stosw
		2035	mov eax, [esi + TCP_SOCKET.SND_NXT]
		2036	bswap eax
		2037	stosd
		2038	mov eax, [esi + TCP_SOCKET.RCV_NXT]
		2039	bswap eax
		2040	stosd
		2041	mov al, 0x50 ; Dataoffset: 20 bytes
		2042	stosb
		2043	mov al, cl
		2044	stosb
		2045	mov ax, [esi + TCP_SOCKET.RCV_WND]
		2046	rol ax, 8
		2047	stosw ; window
		2048	xor eax, eax
		2049	stosd ; checksum + urgentpointer
		2050
		2051	ret
		2052
		2053
		2054
1514	hidnplayr	2055	;-----------------------------------------------------------------
		2056	;
		2057	; TCP_checksum
		2058	;
		2059	; This is the fast procedure to create or check a UDP header
		2060	; - To create a new checksum, the checksum field must be set to 0 before computation
		2061	; - To check an existing checksum, leave the checksum as is,
		2062	; and it will be 0 after this procedure, if it was correct
		2063	;
		2064	; IN: push source ip
		2065	; push dest ip
		2066	;
		2067	; esi = packet ptr
		2068	;
		2069	; OUT: checksum is filled in in packet! (but also in dx)
		2070	;
		2071	;-----------------------------------------------------------------
1249	hidnplayr	2072	align 4
1514	hidnplayr	2073	TCP_checksum:
1254	hidnplayr	2074
1514	hidnplayr	2075	;-------------
		2076	; Pseudoheader
1254	hidnplayr	2077
1514	hidnplayr	2078	; protocol type
		2079	mov edx, IP_PROTO_TCP ; NO shl 8 here ! (it took me ages to figure this one out)
1254	hidnplayr	2080
1514	hidnplayr	2081	; source address
		2082	add dl, [esp+1+4]
		2083	adc dh, [esp+0+4]
		2084	adc dl, [esp+3+4]
		2085	adc dh, [esp+2+4]
1159	hidnplayr	2086
1514	hidnplayr	2087	; destination address
		2088	adc dl, [esp+1+8]
		2089	adc dh, [esp+0+8]
		2090	adc dl, [esp+3+8]
		2091	adc dh, [esp+2+8]
1159	hidnplayr	2092
1514	hidnplayr	2093	; size
		2094	adc dl, cl
		2095	adc dh, ch
1254	hidnplayr	2096
1514	hidnplayr	2097	;---------------------
		2098	; Real header and data
1254	hidnplayr	2099
1514	hidnplayr	2100	push esi
		2101	call checksum_1
		2102	call checksum_2
		2103	pop esi
1254	hidnplayr	2104
1514	hidnplayr	2105	neg [esi+UDP_Packet.Checksum] ; zero will stay zero so we just get the checksum
		2106	add [esi+UDP_Packet.Checksum], dx ; , else we will get (new checksum - old checksum) in the end, wich should be 0 :)
1159	hidnplayr	2107
1514	hidnplayr	2108	ret 8 ; Remove the IPs from stack
1159	hidnplayr	2109
		2110
1514	hidnplayr	2111
		2112
1254	hidnplayr	2113	;---------------------------------------------------------------------------
		2114	;
		2115	; TCP_API
		2116	;
		2117	; This function is called by system function 75
		2118	;
		2119	; IN: subfunction number in bl
		2120	; device number in bh
		2121	; ecx, edx, .. depends on subfunction
		2122	;
		2123	; OUT:
		2124	;
		2125	;---------------------------------------------------------------------------
		2126	align 4
		2127	TCP_API:
		2128
		2129	movzx eax, bh
		2130	shl eax, 2
		2131
		2132	test bl, bl
		2133	jz .packets_tx ; 0
		2134	dec bl
		2135	jz .packets_rx ; 1
		2136
		2137	.error:
		2138	mov eax, -1
		2139	ret
		2140
		2141	.packets_tx:
1514	hidnplayr	2142	add eax, TCP_segments_tx
1254	hidnplayr	2143	mov eax, [eax]
		2144	ret
		2145
		2146	.packets_rx:
1514	hidnplayr	2147	add eax, TCP_segments_rx
1254	hidnplayr	2148	mov eax, [eax]
		2149	ret

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(root)/kernel/branches/net/network/tcp.inc – Rev 1519