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: 1529 $
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
1274	hidnplayr	93	struct tcp_in_queue_entry
		94	.data_ptr dd ?
		95	.data_size dd ?
1514	hidnplayr	96	.offset dd ?
1274	hidnplayr	97	.size:
		98	ends
		99
		100	struct tcp_out_queue_entry
		101	.data_ptr dd ?
		102	.data_size dd ?
1514	hidnplayr	103
1274	hidnplayr	104	.size:
		105	ends
		106
1196	hidnplayr	107	align 4
		108	uglobal
1514	hidnplayr	109	TCP_segments_tx rd IP_MAX_INTERFACES
		110	TCP_segments_rx rd IP_MAX_INTERFACES
		111	TCP_bytes_rx rq IP_MAX_INTERFACES
		112	TCP_bytes_tx rq IP_MAX_INTERFACES
		113	TCP_sequence_num dd ?
1196	hidnplayr	114	endg
		115
		116
		117	;-----------------------------------------------------------------
		118	;
		119	; TCP_init
		120	;
		121	; This function resets all TCP variables
		122	;
		123	;-----------------------------------------------------------------
1529	hidnplayr	124	macro TCP_init {
1196	hidnplayr	125
		126	xor eax, eax
1514	hidnplayr	127	mov edi, TCP_segments_tx
		128	mov ecx, (6*IP_MAX_INTERFACES)
1196	hidnplayr	129	rep stosd
		130
1529	hidnplayr	131	pseudo_random eax
		132	mov [TCP_sequence_num], eax
1196	hidnplayr	133
1529	hidnplayr	134	}
1196	hidnplayr	135
		136
1519	hidnplayr	137	;----------------------
1196	hidnplayr	138	;
1159	hidnplayr	139	;
1519	hidnplayr	140	;----------------------
1529	hidnplayr	141	macro TCP_timer_160ms {
1159	hidnplayr	142
1529	hidnplayr	143	local .loop
		144	local .exit
		145
1514	hidnplayr	146	mov eax, net_sockets
		147	.loop:
		148	mov eax, [eax + SOCKET.NextPtr]
		149	or eax, eax
1159	hidnplayr	150	jz .exit
		151
1514	hidnplayr	152	cmp [eax + SOCKET.Type], IP_PROTO_TCP
		153	jne .loop
1249	hidnplayr	154
1519	hidnplayr	155	dec [eax + TCP_SOCKET.timer_ack]
1514	hidnplayr	156	jnz .loop
1159	hidnplayr	157
1519	hidnplayr	158	DEBUGF 1,"TCP ack for socket %x expired, time to piggyback!\n", eax
1159	hidnplayr	159
1519	hidnplayr	160	push eax
1529	hidnplayr	161	call TCP_respond_socket
1514	hidnplayr	162	pop eax
1159	hidnplayr	163
1519	hidnplayr	164	jmp .loop
1159	hidnplayr	165
		166	.exit:
1519	hidnplayr	167
1529	hidnplayr	168	}
1159	hidnplayr	169
		170
1519	hidnplayr	171	;-----------------------------------------------------------------
1159	hidnplayr	172	;
		173	;
1519	hidnplayr	174	;-----------------------------------------------------------------
1529	hidnplayr	175	macro TCP_timer_640ms {
1159	hidnplayr	176
1529	hidnplayr	177	local .loop
		178	local .exit
		179
1519	hidnplayr	180	; Update TCP sequence number
		181
1514	hidnplayr	182	add [TCP_sequence_num], 64000
1159	hidnplayr	183
1519	hidnplayr	184	; scan through all the active TCP sockets, decrementing ALL timers
		185	; timers do not have the chance to wrap because of the keepalive timer will kill the socket when it expires
1159	hidnplayr	186
1519	hidnplayr	187	mov eax, net_sockets
		188	.loop:
		189	mov eax, [eax + SOCKET.NextPtr]
		190	.check_only:
		191	or eax, eax
		192	jz .exit
1159	hidnplayr	193
1519	hidnplayr	194	cmp [eax + SOCKET.Type], IP_PROTO_TCP
		195	jne .loop
1159	hidnplayr	196
1529	hidnplayr	197	inc [eax + TCP_SOCKET.t_idle]
		198	dec [eax + TCP_SOCKET.timer_retransmission]
1519	hidnplayr	199	jnz .check_more2
1254	hidnplayr	200
1519	hidnplayr	201	DEBUGF 1,"socket %x: Retransmission timer expired\n", eax
1159	hidnplayr	202
1519	hidnplayr	203	push eax
		204	call TCP_output
		205	pop eax
1159	hidnplayr	206
1519	hidnplayr	207	.check_more2:
		208	dec [eax + TCP_SOCKET.timer_keepalive]
		209	jnz .check_more3
1159	hidnplayr	210
1519	hidnplayr	211	DEBUGF 1,"socket %x: Keepalive expired\n", eax
1159	hidnplayr	212
1519	hidnplayr	213	;;; TODO: check socket state and handle accordingly
1318	hidnplayr	214
1519	hidnplayr	215	.check_more3:
		216	dec [eax + TCP_SOCKET.timer_timed_wait]
		217	jnz .check_more5
		218
		219	DEBUGF 1,"socket %x: 2MSL timer expired\n", eax
		220
		221	.check_more5:
		222	dec [eax + TCP_SOCKET.timer_persist]
		223	jnz .loop
		224
		225	DEBUGF 1,"socket %x: persist timer expired\n", eax
		226
		227	jmp .loop
		228	.exit:
1529	hidnplayr	229	}
1519	hidnplayr	230
		231
1529	hidnplayr	232
		233
		234	macro TCP_checksum IP1, IP2 {
		235
		236	;-------------
		237	; Pseudoheader
		238
		239	; protocol type
		240	mov edx, IP_PROTO_TCP
		241
		242	; source address
		243	add dl, byte [IP1+1+4]
		244	adc dh, byte [IP1+0+4]
		245	adc dl, byte [IP1+3+4]
		246	adc dh, byte [IP1+2+4]
		247
		248	; destination address
		249	adc dl, byte [IP2+1+8]
		250	adc dh, byte [IP2+0+8]
		251	adc dl, byte [IP2+3+8]
		252	adc dh, byte [IP2+2+8]
		253
		254	; size
		255	adc dl, cl
		256	adc dh, ch
		257
		258	;---------------------
		259	; Real header and data
		260
		261	push esi
		262	call checksum_1
		263	call checksum_2
		264	pop esi
		265
		266	} ; returns in dx only
		267
		268
		269
1249	hidnplayr	270	;-----------------------------------------------------------------
		271	;
1514	hidnplayr	272	; TCP_input:
1159	hidnplayr	273	;
1514	hidnplayr	274	; IN: [esp] = ptr to buffer
		275	; [esp+4] = buffer size
		276	; ebx = ptr to device struct
		277	; ecx = segment size
		278	; edx = ptr to TCP segment
1196	hidnplayr	279	;
1514	hidnplayr	280	; esi = ipv4 source address
		281	; edi = ipv4 dest address
		282	;
1196	hidnplayr	283	; OUT: /
		284	;
		285	;-----------------------------------------------------------------
1249	hidnplayr	286	align 4
1514	hidnplayr	287	TCP_input:
1159	hidnplayr	288
1529	hidnplayr	289	DEBUGF 1,"TCP_input size=%u\n", ecx
1514	hidnplayr	290	; 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	291
1514	hidnplayr	292	movzx eax, [edx + TCP_segment.DataOffset]
		293	and eax, 0xf0
1529	hidnplayr	294	shr al, 2
1514	hidnplayr	295
1529	hidnplayr	296	DEBUGF 1,"headersize=%u\n", eax
1514	hidnplayr	297
		298	cmp eax, 20
		299	jl .drop
		300
		301	;-------------------------------
		302	; Now, re-calculate the checksum
		303
1529	hidnplayr	304	push eax ecx edx
		305	pushw [edx + TCP_segment.Checksum]
		306	mov [edx + TCP_segment.Checksum], 0
		307	push esi edi
1514	hidnplayr	308	mov esi, edx
1529	hidnplayr	309	TCP_checksum
		310	pop esi edi ; yes, swap them (we dont need dest addr)
		311	pop cx ; previous checksum
		312	cmp cx, dx
		313	pop edx ecx esi
1514	hidnplayr	314	jnz .drop
		315
		316	DEBUGF 1,"Checksum is correct\n"
		317
1529	hidnplayr	318	sub ecx, esi ; update packet size
		319	jl .drop
		320
1514	hidnplayr	321	;-----------------------------------------------------------------------------------------
		322	; Check if this packet has a timestamp option (We do it here so we can process it quickly)
		323
1529	hidnplayr	324	cmp esi, 20 + 12 ; Timestamp option is 12 bytes
1514	hidnplayr	325	jl .no_timestamp
		326	je .is_ok
		327
1529	hidnplayr	328	cmp byte [edx + TCP_segment.Data + 12], TCP_OPT_EOL ; end of option list
1514	hidnplayr	329	jne .no_timestamp
		330
		331	.is_ok:
		332	test [edx + TCP_segment.Flags], TH_SYN ; SYN flag must not be set
		333	jnz .no_timestamp
		334
		335	cmp dword [edx + TCP_segment.Data], 0x0101080a ; Timestamp header
		336	jne .no_timestamp
		337
		338	DEBUGF 1,"timestamp ok\n"
		339
1529	hidnplayr	340	; TODO: Parse the option
1514	hidnplayr	341	; TODO: Set a Bit in the TCP to tell all options are parsed
		342
		343	.no_timestamp:
		344
		345	;-------------------------------------------
		346	; Convert Big-endian values to little endian
		347
		348	ntohld [edx + TCP_segment.SequenceNumber]
		349	ntohld [edx + TCP_segment.AckNumber]
		350
		351	ntohlw [edx + TCP_segment.Window]
		352	ntohlw [edx + TCP_segment.UrgentPointer]
1529	hidnplayr	353	ntohlw [edx + TCP_segment.SourcePort]
		354	ntohlw [edx + TCP_segment.DestinationPort]
1514	hidnplayr	355
		356	;------------------------------------------------------------
		357	; Next thing to do is find the TCB (thus, the socket pointer)
		358
1274	hidnplayr	359	; IP Packet TCP Destination Port = local Port
1514	hidnplayr	360	; (IP Packet SenderAddress = Remote IP) OR (Remote IP = 0)
1318	hidnplayr	361	; (IP Packet TCP Source Port = remote Port) OR (remote Port = 0)
1159	hidnplayr	362
		363	mov ebx, net_sockets
		364
1249	hidnplayr	365	.socket_loop:
1514	hidnplayr	366	mov ebx, [ebx + SOCKET.NextPtr]
1159	hidnplayr	367	or ebx, ebx
1514	hidnplayr	368	jz .drop_with_reset
1159	hidnplayr	369
1514	hidnplayr	370	cmp [ebx + SOCKET.Type], IP_PROTO_TCP
1249	hidnplayr	371	jne .socket_loop
1159	hidnplayr	372
1514	hidnplayr	373	mov ax, [edx + TCP_segment.DestinationPort]
		374	cmp [ebx + TCP_SOCKET.LocalPort], ax
		375	jne .socket_loop
		376
		377	mov eax, [ebx + IP_SOCKET.RemoteIP]
1529	hidnplayr	378	cmp eax, edi ; sender IP
1249	hidnplayr	379	je @f
		380	test eax, eax
1514	hidnplayr	381	jnz .socket_loop
1249	hidnplayr	382	@@:
1159	hidnplayr	383
1514	hidnplayr	384	mov ax, [ebx + TCP_SOCKET.RemotePort]
		385	cmp [edx + TCP_segment.SourcePort] , ax
1274	hidnplayr	386	je .found_socket
1249	hidnplayr	387	test ax, ax
1254	hidnplayr	388	jnz .socket_loop
1274	hidnplayr	389	.found_socket:
1529	hidnplayr	390	DEBUGF 1,"Socket ptr: %x\n", ebx
1254	hidnplayr	391
1514	hidnplayr	392	; ebx now contains the pointer to the socket
1257	hidnplayr	393
1514	hidnplayr	394	;----------------------------
		395	; Check if socket isnt closed
		396
1529	hidnplayr	397	cmp [ebx + TCP_SOCKET.t_state], TCB_CLOSED
1514	hidnplayr	398	je .drop
		399
		400	;----------------
		401	; Lock the socket
		402
1529	hidnplayr	403	;; add ebx, SOCKET.lock ; TODO: figure out if we should lock now already
		404	;; call wait_mutex
		405	;; sub ebx, SOCKET.lock
1159	hidnplayr	406
1529	hidnplayr	407	DEBUGF 1,"Socket locked\n"
1159	hidnplayr	408
1529	hidnplayr	409	;----------------------------------------------------------------------------------------
		410	; unscale the window into a 32 bit value (notice that SND_SCALE must be initialised to 0)
		411
1514	hidnplayr	412	movzx eax, [edx + TCP_segment.Window]
1529	hidnplayr	413	push cx
		414	mov cl, [ebx + TCP_SOCKET.SND_SCALE]
1514	hidnplayr	415	shl eax, cl
1529	hidnplayr	416	pop cx
1514	hidnplayr	417
1529	hidnplayr	418	;;;; do something with eax
1514	hidnplayr	419
		420	;-----------------------------------
		421	; Is this socket a listening socket?
		422
1529	hidnplayr	423	; test [ebx + SOCKET.options], SO_ACCEPTCON
		424	; jnz .listening_socket ;;;;; TODO
1514	hidnplayr	425
1529	hidnplayr	426	;-------------------------------------
		427	; Reset idle timer and keepalive timer
1514	hidnplayr	428
1529	hidnplayr	429	mov [ebx + TCP_SOCKET.t_idle], 0
		430	mov [ebx + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval
1514	hidnplayr	431
1529	hidnplayr	432	;--------------------
		433	; Process TCP options
1514	hidnplayr	434
1529	hidnplayr	435	cmp esi, 20 ; esi is headersize
		436	je .no_options
1514	hidnplayr	437
1529	hidnplayr	438	DEBUGF 1,"Segment has options\n"
1514	hidnplayr	439
1529	hidnplayr	440	test [ebx + TCP_SOCKET.t_state], TCB_LISTEN ; no options when in listen state
		441	jz .no_options
1514	hidnplayr	442
1529	hidnplayr	443	lea edi, [edx + TCP_segment.Data]
		444	lea eax, [edx + esi]
1514	hidnplayr	445
1529	hidnplayr	446	.opt_loop:
		447	cmp edi, eax
		448	jge .no_options
1514	hidnplayr	449
1529	hidnplayr	450	cmp byte [edi], TCP_OPT_EOL ; end of option list?
		451	jz .no_options
1514	hidnplayr	452
1529	hidnplayr	453	cmp byte [edi], TCP_OPT_NOP ; nop ?
		454	jz .opt_nop
1514	hidnplayr	455
1529	hidnplayr	456	cmp byte [edi], TCP_OPT_MAXSEG
		457	je .opt_maxseg
1514	hidnplayr	458
1529	hidnplayr	459	cmp byte [edi], TCP_OPT_WINDOW
		460	je .opt_window
1514	hidnplayr	461
1529	hidnplayr	462	cmp byte [edi], TCP_OPT_TIMESTAMP
		463	je .opt_timestamp
1514	hidnplayr	464
1529	hidnplayr	465	jmp .no_options ; If we reach here, some unknown options were received, skip them all!
1514	hidnplayr	466
1529	hidnplayr	467	.opt_nop:
		468	inc edi
		469	jmp .opt_loop
1514	hidnplayr	470
1529	hidnplayr	471	.opt_maxseg:
		472	cmp byte [edi+1], 4
		473	jne .no_options ; error occured, ignore all options!
1514	hidnplayr	474
1529	hidnplayr	475	test [edx + TCP_segment.Flags], TH_SYN
		476	jz @f
		477
		478	DEBUGF 1,"Got maxseg option"
		479
		480	;;;;;
		481	@@:
		482	add edi, 4
		483	jmp .opt_loop
		484
		485
		486	.opt_window:
		487	cmp byte [edi+1], 3
		488	jne .no_options
		489
		490	test [edx + TCP_segment.Flags], TH_SYN
		491	jz @f
		492
		493	DEBUGF 1,"Got window option"
		494
		495	;;;;;
		496	@@:
		497	add edi, 3
		498	jmp .opt_loop
		499
		500
		501	.opt_timestamp:
		502	cmp byte [edi+1], 10
		503	jne .no_options
		504
		505	DEBUGF 1,"Got timestamp option"
		506
		507	;;;;;
		508
		509	add edi, 10
		510	jmp .opt_loop
		511
		512	.no_options:
		513
1514	hidnplayr	514	;-----------------------------------------------------------------------
		515	; Time to do some header prediction (Original Principle by Van Jacobson)
		516
		517	; There are two common cases for an uni-directional data transfer.
		518	;
		519	; General rule: the packets has no control flags, is in-sequence,
		520	; window width didnt change and we're not retransmitting.
		521	;
		522	; Second rules:
		523	; - If the length is 0 and the ACK moved forward, we're the sender side of the transfer.
		524	; In this case we'll free the ACK'ed data and notify higher levels that we have free space in buffer
		525	;
		526	; - If the length is not 0 and the ACK didn't move, we're the receiver side of the transfer.
		527	; If the packets are in order (data queue is empty), add the data to the socket buffer and request a delayed ACK
		528
1529	hidnplayr	529	cmp [ebx + TCP_SOCKET.t_state], TCB_ESTABLISHED
1514	hidnplayr	530	jnz .not_uni_xfer
		531
1529	hidnplayr	532	test [edx + TCP_segment.Flags], TH_SYN + TH_FIN + TH_RST + TH_URG
1514	hidnplayr	533	jnz .not_uni_xfer
		534
1529	hidnplayr	535	test [edx + TCP_segment.Flags], TH_ACK
1514	hidnplayr	536	jz .not_uni_xfer
		537
		538	mov eax, [edx + TCP_segment.SequenceNumber]
		539	cmp eax, [ebx + TCP_SOCKET.RCV_NXT]
		540	jne .not_uni_xfer
		541
1529	hidnplayr	542	movzx eax, [edx + TCP_segment.Window] ;;;;; (should use pre-calculated value isntead: todo: figure out where to store it)
1514	hidnplayr	543	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		544	jne .not_uni_xfer
		545
		546	mov eax, [ebx + TCP_SOCKET.SND_NXT]
		547	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		548	jne .not_uni_xfer
		549
		550	;---------------------------------------
		551	; check if we are sender in the uni-xfer
		552
		553	; If the following 4 conditions are all true, this segment is a pure ACK.
		554	;
1529	hidnplayr	555	; - The segment contains no data.
		556	test ecx, ecx
1514	hidnplayr	557	jnz .not_sender
1274	hidnplayr	558
1529	hidnplayr	559	; - The congestion window is greater than or equal to the current send window.
1514	hidnplayr	560	; 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.
		561	mov eax, [ebx + TCP_SOCKET.SND_CWND]
		562	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		563	jl .not_uni_xfer
1318	hidnplayr	564
1529	hidnplayr	565	; - The acknowledgment field in the segment is less than or equal to the maximum sequence number sent.
		566	mov ecx, [edx + TCP_segment.AckNumber]
		567	cmp ecx, [ebx + TCP_SOCKET.SND_MAX]
		568	jg .not_uni_xfer
		569
		570	; - The acknowledgment field in the segment is greater than the largest unacknowledged sequence number.
		571	sub ecx, [ebx + TCP_SOCKET.SND_UNA]
		572	jle .not_uni_xfer
		573
1514	hidnplayr	574	DEBUGF 1,"Header prediction: we are sender\n"
1274	hidnplayr	575
1514	hidnplayr	576	;---------------------------------
		577	; Packet is a pure ACK, process it
1274	hidnplayr	578
1514	hidnplayr	579	; Update RTT estimators
1159	hidnplayr	580
1514	hidnplayr	581	; Delete acknowledged bytes from send buffer
1529	hidnplayr	582	; notice how ecx already holds number of bytes ack-ed
1254	hidnplayr	583
1529	hidnplayr	584	lea eax, [ebx + snd]
		585	call SOCKET_ring_free
		586
1514	hidnplayr	587	; Stop retransmit timer
1519	hidnplayr	588	mov [ebx + TCP_SOCKET.timer_ack], 0
1159	hidnplayr	589
1514	hidnplayr	590	; Awaken waiting processes
1519	hidnplayr	591	mov eax, ebx
		592	call SOCKET_notify_owner
1318	hidnplayr	593
1514	hidnplayr	594	; Generate more output
1519	hidnplayr	595	call TCP_output
1254	hidnplayr	596
1514	hidnplayr	597	jmp .drop
1159	hidnplayr	598
1514	hidnplayr	599	;-------------------------------------------------
		600	; maybe we are the receiver in the uni-xfer then..
		601
		602	.not_sender:
1529	hidnplayr	603	; - The amount of data in the segment is greater than 0 (data count is in ecx)
1514	hidnplayr	604
1529	hidnplayr	605	; - The acknowledgment field equals the largest unacknowledged sequence number. This means no data is acknowledged by this segment.
1514	hidnplayr	606	mov eax, [edx + TCP_segment.AckNumber]
		607	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
		608	jne .not_uni_xfer
		609
1529	hidnplayr	610	; - The reassembly list of out-of-order segments for the connection is empty (seg_next equals tp). ;;;;;;;
1514	hidnplayr	611
		612	jnz .not_uni_xfer
		613
		614	;-------------------------------------
		615	; Complete processing of received data
		616
		617	DEBUGF 1,"header prediction: we are receiver\nreceiving %u bytes of data\n", ecx
		618
1529	hidnplayr	619	add esi, edx
		620	lea eax, [ebx + rcv]
		621	call SOCKET_ring_add ; Add the data to the socket buffer
1514	hidnplayr	622
1529	hidnplayr	623	add [ebx + TCP_SOCKET.RCV_NXT], ecx ; Update sequence number with number of bytes we have copied
		624	or [ebx + TCP_SOCKET.t_flags], TF_DELACK ; Set delayed ack flag
1514	hidnplayr	625
		626	jmp .drop
		627
		628	;----------------------------------------------------
1529	hidnplayr	629	; Header prediction failed, doing it the slow way.. ;;;;; current implementation of header prediction destroys some regs (ecx) !!
1514	hidnplayr	630
		631	.not_uni_xfer:
		632
		633	DEBUGF 1,"Header prediction failed\n"
		634
		635	;------------------------------
		636	; Calculate receive window size
		637
		638	;;;;
		639
		640	;-------------------------
		641	; TCP slow input procedure
		642
		643	DEBUGF 1,"TCP slow input procedure\n"
		644
1529	hidnplayr	645	cmp [ebx + TCP_SOCKET.t_state], TCB_LISTEN
1514	hidnplayr	646	je .LISTEN
		647
1529	hidnplayr	648	cmp [ebx + TCP_SOCKET.t_state], TCB_SYN_SENT
1514	hidnplayr	649	je .SYN_SENT
		650
		651	;--------------------------------------------
		652	; Protection Against Wrapped Sequence Numbers
		653
		654	; First, check timestamp if present
		655
		656	;;;; TODO
		657
		658	; Then, check if at least some bytes of data are within window
		659
		660	;;;; TODO
		661
		662	jmp .trim_then_step6
		663
1529	hidnplayr	664	;-------------
		665	; Passive Open
		666
1249	hidnplayr	667	align 4
1514	hidnplayr	668	.LISTEN:
1196	hidnplayr	669
1514	hidnplayr	670	DEBUGF 1,"TCP state: listen\n"
1159	hidnplayr	671
1514	hidnplayr	672	test [edx + TCP_segment.Flags], TH_RST
		673	jnz .drop
1159	hidnplayr	674
1514	hidnplayr	675	test [edx + TCP_segment.Flags], TH_ACK
		676	jnz .drop_with_reset
1159	hidnplayr	677
1514	hidnplayr	678	test [edx + TCP_segment.Flags], TH_SYN
		679	jz .drop
1159	hidnplayr	680
1529	hidnplayr	681	; TODO: find sender ip address somewhere!
1514	hidnplayr	682	; TODO: check if it's a broadcast or multicast, and drop if so
1159	hidnplayr	683
1529	hidnplayr	684	call SOCKET_fork
		685	jz .drop ; if we could not open a new connection, drop segment (;;;; should we send RST too?)
1514	hidnplayr	686
1529	hidnplayr	687	;-----------------------
		688	; Fill in some variables
1514	hidnplayr	689
1529	hidnplayr	690	add [TCP_sequence_num], 64000
1514	hidnplayr	691
1529	hidnplayr	692	push [edx + TCP_segment.SourcePort]
		693	pop [eax + TCP_SOCKET.RemotePort]
1514	hidnplayr	694
1529	hidnplayr	695	push [edx + TCP_segment.SequenceNumber]
		696	pop [eax + TCP_SOCKET.IRS]
1159	hidnplayr	697
1529	hidnplayr	698	push [eax + TCP_SOCKET.ISS]
		699	pop [eax + TCP_SOCKET.SND_NXT]
1159	hidnplayr	700
1529	hidnplayr	701	mov [eax + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		702	mov [eax + TCP_SOCKET.t_flags], TF_ACKNOW
		703	mov [eax + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval
1159	hidnplayr	704
1529	hidnplayr	705	mov ebx, eax
1159	hidnplayr	706
1514	hidnplayr	707	jmp .trim_then_step6
1159	hidnplayr	708
1254	hidnplayr	709
1529	hidnplayr	710	;------------
		711	; Active Open
1159	hidnplayr	712
1514	hidnplayr	713	align 4
		714	.SYN_SENT:
1281	hidnplayr	715
1514	hidnplayr	716	DEBUGF 1,"TCP state: syn_sent\n"
1159	hidnplayr	717
1514	hidnplayr	718	test [edx + TCP_segment.Flags], TH_ACK
		719	jz @f
1281	hidnplayr	720
1514	hidnplayr	721	mov eax, [edx + TCP_segment.AckNumber]
		722	cmp eax, [ebx + TCP_SOCKET.ISS]
		723	jle .drop_with_reset
1281	hidnplayr	724
1529	hidnplayr	725	DEBUGF 1,"snd_max = %x\n", [ebx + TCP_SOCKET.SND_MAX] ;;; TODO: set this, but where?
		726
		727	; mov eax, [edx + TCP_segment.AckNumber]
		728	;; cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		729	;; jg .drop_with_reset
1514	hidnplayr	730	@@:
1281	hidnplayr	731
1514	hidnplayr	732	test [edx + TCP_segment.Flags], TH_RST
		733	jz @f
1281	hidnplayr	734
1514	hidnplayr	735	test [edx + TCP_segment.Flags], TH_ACK
		736	jz .drop
1281	hidnplayr	737
1514	hidnplayr	738	;tp = tcp_drop(tp, ECONNREFUSED)
1159	hidnplayr	739
1514	hidnplayr	740	jmp .drop
		741	@@:
1159	hidnplayr	742
1514	hidnplayr	743	test [edx + TCP_segment.Flags], TH_SYN
		744	jz .drop
1318	hidnplayr	745
1529	hidnplayr	746	; at this point, segment seems to be valid
		747
1514	hidnplayr	748	test [edx + TCP_segment.Flags], TH_ACK
1529	hidnplayr	749	jz .no_syn_ack
1514	hidnplayr	750
1529	hidnplayr	751	; now, process received SYN in response to an active open
		752
1514	hidnplayr	753	mov eax, [edx + TCP_segment.AckNumber]
		754	mov [ebx + TCP_SOCKET.SND_UNA], eax
		755	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		756	jle @f
		757	mov [ebx + TCP_SOCKET.SND_NXT], eax
1529	hidnplayr	758	@@:
1514	hidnplayr	759
1529	hidnplayr	760	.no_syn_ack:
1514	hidnplayr	761
1529	hidnplayr	762	mov [ebx + TCP_SOCKET.timer_retransmission], 0 ; disable retransmission
1514	hidnplayr	763
1529	hidnplayr	764	push [edx + TCP_segment.SequenceNumber]
		765	pop [ebx + TCP_SOCKET.IRS]
		766
		767	;;; TODO: tcp_rcvseqinit
		768
		769	mov [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
		770
		771	mov eax, [ebx + TCP_SOCKET.SND_UNA]
		772	cmp eax, [ebx + TCP_SOCKET.ISS]
		773	jle .simultaneous_open
		774
		775	test [edx + TCP_segment.Flags], TH_ACK
		776	jz .simultaneous_open
		777
		778	DEBUGF 1,"TCP: active open\n"
		779
		780	; TODO: update stats
1514	hidnplayr	781	; TODO: set socket state to connected
		782
		783	mov [ebx + TCP_SOCKET.t_state], TCB_ESTABLISHED
		784
		785	; TODO: check if we should scale the connection (567-572)
		786	; TODO: update RTT estimators
		787
1529	hidnplayr	788	jmp .trimthenstep6
1514	hidnplayr	789
1529	hidnplayr	790	.simultaneous_open:
1514	hidnplayr	791
1529	hidnplayr	792	DEBUGF 1,"TCP: simultaneous open\n"
1514	hidnplayr	793	; We have received a syn but no ACK, so we are having a simultaneous open..
		794	mov [ebx + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		795
		796	;-------------------------------------
		797	; Common processing for receipt of SYN
		798
		799	.trimthenstep6:
		800
		801	inc [edx + TCP_segment.SequenceNumber]
		802
		803	cmp cx, [ebx + TCP_SOCKET.RCV_WND]
		804	jle @f
		805
		806	movzx eax, cx
		807	sub ax, [ebx + TCP_SOCKET.RCV_WND]
		808	; TODO: 592
		809	mov cx, [ebx + TCP_SOCKET.RCV_WND]
		810	; TODO...
		811	@@:
		812	;;;;;
1529	hidnplayr	813	jmp .step6
1514	hidnplayr	814
		815
		816
		817
		818
1529	hidnplayr	819	.trim_then_step6:
1159	hidnplayr	820
1529	hidnplayr	821	DEBUGF 1,"Trimming window\n"
1159	hidnplayr	822
1514	hidnplayr	823	;----------------------------
		824	; trim any data not in window
1159	hidnplayr	825
1514	hidnplayr	826	mov eax, [ebx + TCP_SOCKET.RCV_NXT]
		827	sub eax, [edx + TCP_segment.SequenceNumber]
1318	hidnplayr	828
1514	hidnplayr	829	test eax, eax
		830	jz .no_drop
1274	hidnplayr	831
1514	hidnplayr	832	test [edx + TCP_segment.Flags], TH_SYN
		833	jz .no_drop
		834
		835	and [edx + TCP_segment.Flags], not (TH_SYN)
		836	inc [edx + TCP_segment.SequenceNumber]
		837
		838	cmp [edx + TCP_segment.UrgentPointer], 1
		839	jl @f
		840
		841	dec [edx + TCP_segment.UrgentPointer]
		842
		843	jmp .no_drop
		844	@@:
		845
		846	and [edx + TCP_segment.Flags], not (TH_URG)
		847	dec eax
		848
		849	.no_drop:
		850
1529	hidnplayr	851	DEBUGF 1,"Going to drop %u bytes of data", eax
		852
1514	hidnplayr	853	; eax holds number of bytes to drop
		854
		855	;----------------------------------
		856	; Check for entire duplicate packet
		857
		858	cmp eax, ecx
		859	jge .duplicate
		860
		861	;;; TODO: figure 28.30
		862
		863	;------------------------
		864	; Check for duplicate FIN
		865
		866	test [edx + TCP_segment.Flags], TH_FIN
		867	jz @f
		868	inc ecx
		869	cmp eax, ecx
		870	dec ecx
		871	jne @f
		872
		873	mov eax, ecx
		874	and [edx + TCP_segment.Flags], not TH_FIN
1529	hidnplayr	875	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1514	hidnplayr	876	jmp .no_duplicate
		877	@@:
		878
		879	; Handle the case when a bound socket connects to itself
		880	; Allow packets with a SYN and an ACKto continue with the processing
		881
		882	;-------------------------------------
		883	; Generate duplicate ACK if nescessary
		884
		885	; This code also handles simultaneous half-open or self-connects
		886
		887	test eax, eax
		888	jnz .drop_after_ack
		889
		890	cmp [edx + TCP_segment.Flags], TH_ACK
		891	jz .drop_after_ack
		892
		893	.duplicate:
		894
1529	hidnplayr	895	DEBUGF 1,"Duplicate received"
		896
1514	hidnplayr	897	;----------------------------------------
		898	; Update statistics for duplicate packets
		899
		900	;;; TODO
		901
1529	hidnplayr	902	jmp .drop ;;; DROP the packet ??
1514	hidnplayr	903
		904	.no_duplicate:
		905
		906	;-----------------------------------------------
		907	; Remove duplicate data and update urgent offset
		908
		909	add [edx + TCP_segment.SequenceNumber], eax
		910
		911	;;; TODO
		912
		913	sub [edx + TCP_segment.UrgentPointer], ax
		914	jg @f
		915
		916	and [edx + TCP_segment.Flags], not (TH_URG)
		917	mov [edx + TCP_segment.UrgentPointer], 0
		918	@@:
		919
		920	;--------------------------------------------------
		921	; Handle data that arrives after process terminates
		922
		923	cmp [ebx + SOCKET.PID], 0
		924	jge @f
		925
		926	cmp [ebx + TCP_SOCKET.t_state], TCB_CLOSE_WAIT
		927	jle @f
		928
		929	test ecx, ecx
		930	jz @f
		931
		932	;;; Close the socket
		933	;;; update stats
		934
		935	jmp .drop_with_reset
		936
		937	@@:
		938
		939	;----------------------------------------
		940	; Remove data beyond right edge of window
		941
		942	mov eax, [edx + TCP_segment.SequenceNumber]
		943	add eax, ecx
		944	sub eax, [ebx + TCP_SOCKET.RCV_NXT]
		945	sub ax, [ebx + TCP_SOCKET.RCV_WND]
		946
		947	; eax now holds the number of bytes to drop
		948
		949	jle .no_excess_data
		950
		951	;;; TODO: update stats
		952
		953	cmp eax, ecx
		954	jl .dont_drop_all
		955
		956	;;; TODO 700-736
		957
		958	.dont_drop_all:
		959
		960	.no_excess_data:
		961
		962	;-----------------
		963	; Record timestamp
		964
		965	;;; TODO 737-746
		966
		967	;------------------
		968	; Process RST flags
		969
		970	test [edx + TCP_segment.Flags], TH_RST
		971	jz .rst_skip
		972
1529	hidnplayr	973	DEBUGF 1,"Got an RST flag"
		974
1514	hidnplayr	975	mov eax, [ebx + TCP_SOCKET.t_state]
		976	shl eax, 2
		977	jmp dword [eax + .rst_sw_list]
		978
		979	.rst_sw_list:
		980	dd .rst_skip ;TCB_CLOSED
		981	dd .rst_skip ;TCB_LISTEN
		982	dd .rst_skip ;TCB_SYN_SENT
		983	dd .econnrefused ;TCB_SYN_RECEIVED
		984	dd .econnreset ;TCB_ESTABLISHED
		985	dd .econnreset ;TCB_CLOSE_WAIT
		986	dd .econnreset ;TCB_FIN_WAIT_1
		987	dd .rst_close ;TCB_CLOSING
		988	dd .rst_close ;TCB_LAST_ACK
		989	dd .econnreset ;TCB_FIN_WAIT_2
		990	dd .rst_close ;TCB_TIMED_WAIT
		991
		992	.econnrefused:
		993
1529	hidnplayr	994	DEBUGF 1,"Connection refused"
		995
1514	hidnplayr	996	;;; TODO: debug info
		997
		998	jmp .close
		999
		1000	.econnreset:
		1001
1529	hidnplayr	1002	DEBUGF 1,"Connection reset"
		1003
1514	hidnplayr	1004	;;; TODO: debug info
1529	hidnplayr	1005	.close:
1514	hidnplayr	1006
1529	hidnplayr	1007	DEBUGF 1,"Closing connection"
		1008
1514	hidnplayr	1009	;;; update stats
		1010
		1011	.rst_close:
		1012
1529	hidnplayr	1013	DEBUGF 1,"Closing with reset"
		1014
1514	hidnplayr	1015	;;; Close the socket
		1016	jmp .drop
		1017
		1018	.rst_skip:
		1019
		1020	;--------------------------------------
		1021	; handle SYN-full and ACK-less segments
		1022
		1023	test [edx + TCP_segment.Flags], TH_SYN
		1024	jz @f
		1025
		1026	;;; tcp_drop ( ECONNRESET)
		1027	jmp .drop_with_reset
		1028
		1029	test [edx + TCP_segment.Flags], TH_ACK
		1030	jz .drop
		1031
		1032	;----------------
		1033	; Process the ACK
		1034
		1035	cmp [ebx + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		1036	jg .ack_dup
		1037	jl .ack_nodup
		1038
		1039	;;;;;
		1040
		1041	.ack_dup:
		1042
		1043	;;;;
		1044
		1045	.ack_nodup:
		1046
		1047	;;;; 887
		1048
		1049	;-------------------------------------------------
1519	hidnplayr	1050	; If the congestion window was inflated to account
1514	hidnplayr	1051	; for the other side's cached packets, retrace it
		1052
		1053	;;;; 888 - 902
		1054
		1055
		1056	;------------------------------------------
		1057	; RTT measurements and retransmission timer
		1058
		1059	;;;;; 903 - 926
		1060
1519	hidnplayr	1061	mov [ebx + TCP_SOCKET.timer_retransmission], 0
1514	hidnplayr	1062
1519	hidnplayr	1063	mov eax, [ebx + TCP_SOCKET.SND_MAX]
		1064	cmp eax, [edx + TCP_segment.AckNumber]
		1065	je .all_outstanding
		1066	mov [ebx + TCP_SOCKET.timer_retransmission], 120 ;;;; TODO: correct this value
		1067	.all_outstanding:
		1068
		1069
1514	hidnplayr	1070	;-------------------------------------------
		1071	; Open congestion window in response to ACKs
		1072
		1073	;;;;
		1074
		1075
		1076	;------------------------------------------
		1077	; Remove acknowledged data from send buffer
		1078
1529	hidnplayr	1079	lea eax, [ebx + snd]
		1080	mov ecx, ecx ;;;; 943 - 956
		1081	call SOCKET_ring_free
1514	hidnplayr	1082
		1083	;---------------------------------------
		1084	; Wake up process waiting on send buffer
		1085
1529	hidnplayr	1086	mov eax, ebx
		1087	call SOCKET_notify_owner
1514	hidnplayr	1088
		1089	mov eax, [ebx + TCP_SOCKET.t_state]
		1090	shl eax, 2
		1091	jmp dword [eax + .ACK_sw_list]
		1092
		1093	.ACK_sw_list:
		1094	dd .step6 ;TCB_CLOSED
		1095	dd .step6 ;TCB_LISTEN
		1096	dd .step6 ;TCB_SYN_SENT
		1097	dd .step6 ;TCB_SYN_RECEIVED
		1098	dd .step6 ;TCB_ESTABLISHED
		1099	dd .step6 ;TCB_CLOSE_WAIT
		1100	dd ._963 ;TCB_FIN_WAIT_1
		1101	dd ._958 ;TCB_CLOSING
		1102	dd ._999 ;TCB_LAST_ACK
		1103	dd .step6 ;TCB_FIN_WAIT_2
		1104	dd ._1010 ;TCB_TIMED_WAIT
		1105
		1106
		1107	._963:
		1108
		1109
		1110	jmp .step6
		1111
		1112
		1113	._958:
		1114
		1115	jmp .step6
		1116
		1117	._999:
		1118
		1119	jmp .step6
		1120
		1121
		1122	._1010:
		1123
		1124	jmp .step6
		1125
		1126
		1127
		1128	align 4
		1129	.step6:
		1130
		1131	DEBUGF 1,"step 6\n"
		1132
		1133	;--------------------------
		1134	; update window information
		1135
		1136	test [edx + TCP_segment.Flags], TH_ACK
		1137	jz .no_window_update
		1138
		1139	mov eax, [ebx + TCP_SOCKET.SND_WL1]
		1140	cmp eax, [edx + TCP_segment.SequenceNumber]
		1141
		1142	;;;; 1021
		1143
		1144	;----------------------------------
		1145	; Keep track of pure window updates
		1146
		1147	test ecx, ecx
		1148	jz @f
		1149
		1150	mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1151	cmp eax, [edx + TCP_segment.AckNumber]
		1152	jne @f
		1153
		1154	;; mov eax, tiwin
		1155	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		1156	jle @f
		1157
		1158	;;; update stats
		1159
		1160	@@:
		1161
		1162	;; mov eax, incoming window
		1163	cmp eax, [ebx + TCP_SOCKET.max_sndwnd]
		1164	jle @f
		1165	mov [ebx + TCP_SOCKET.max_sndwnd], eax
		1166	@@:
		1167	mov [ebx + TCP_SOCKET.SND_WND], eax
		1168
		1169	mov eax, [edx + TCP_segment.SequenceNumber]
		1170	mov [ebx + TCP_SOCKET.SND_WL1], eax
		1171
		1172	mov eax, [edx + TCP_segment.AckNumber]
		1173	mov [ebx + TCP_SOCKET.SND_WL2], eax
		1174
		1175	;;; needoutput = 1
		1176
		1177	.no_window_update:
		1178
		1179	;-----------------
		1180	; process URG flag
		1181
		1182	test [edx + TCP_segment.Flags], TH_URG
		1183	jz .not_urgent
		1184
		1185	cmp [edx + TCP_segment.UrgentPointer], 0
		1186	jz .not_urgent
		1187
		1188	cmp [ebx + TCP_SOCKET.t_state], TCB_TIMED_WAIT
		1189	je .not_urgent
		1190
		1191	; Ignore bogus urgent offsets
		1192
		1193	;;; 1040-1050
		1194
		1195	movzx eax, [edx + TCP_segment.UrgentPointer]
1529	hidnplayr	1196	add eax, [ebx + rcv.size]
1514	hidnplayr	1197	cmp eax, SOCKET_MAXDATA
		1198	jle .not_urgent
		1199
		1200	mov [edx + TCP_segment.UrgentPointer], 0
		1201	and [edx + TCP_segment.Flags], not (TH_URG)
		1202	jmp .do_data
		1203
		1204	.not_urgent:
		1205
		1206	;--------------------------------------
		1207	; processing of received urgent pointer
		1208
1529	hidnplayr	1209	;;; TODO (1051-1093)
1514	hidnplayr	1210
1529	hidnplayr	1211	;--------------------------------
		1212	; process the data in the segment
1514	hidnplayr	1213
1529	hidnplayr	1214	.do_data:
1514	hidnplayr	1215
1529	hidnplayr	1216	DEBUGF 1,"TCP: do data:\n"
1514	hidnplayr	1217
		1218	test [edx + TCP_segment.Flags], TH_FIN
1529	hidnplayr	1219	jnz .process_fin
1514	hidnplayr	1220
1529	hidnplayr	1221	test [ebx + TCP_SOCKET.t_state], TCB_FIN_WAIT_1
1514	hidnplayr	1222	jge .dont_do_data
		1223
		1224	DEBUGF 1,"Processing data in segment\n"
		1225
		1226	;;; NOW, process the data
		1227
		1228	jmp .final_processing
		1229
		1230
		1231	.dont_do_data:
		1232
		1233	;---------------
		1234	; FIN processing
		1235
		1236	.process_fin:
		1237
		1238	DEBUGF 1,"Processing FIN\n"
		1239
		1240	mov eax, [ebx + TCP_SOCKET.t_state]
		1241	shl eax, 2
		1242	jmp dword [eax + .FIN_sw_list]
		1243
		1244	.FIN_sw_list:
		1245	dd .no_fin ;TCB_CLOSED
		1246	dd .no_fin ;TCB_LISTEN
		1247	dd .no_fin ;TCB_SYN_SENT
		1248	dd ._1131 ;TCB_SYN_RECEIVED
		1249	dd ._1131 ;TCB_ESTABLISHED
		1250	dd .no_fin ;TCB_CLOSE_WAIT
		1251	dd ._1139 ;TCB_FIN_WAIT_1
		1252	dd .no_fin ;TCB_CLOSING
		1253	dd .no_fin ;TCB_LAST_ACK
		1254	dd ._1147 ;TCB_FIN_WAIT_2
		1255	dd ._1156 ;TCB_TIMED_WAIT
		1256
		1257
		1258
		1259	._1131:
		1260
		1261	._1139:
		1262
		1263	._1147:
		1264
		1265	._1156:
		1266
		1267
		1268	.no_fin:
		1269
		1270	;-----------------
		1271	; Final processing
		1272
		1273	.final_processing:
		1274
		1275	DEBUGF 1,"Final processing\n"
		1276
		1277	;;; if debug enabled, output packet
		1278
		1279	;test ;;;needoutput = 1
		1280	;jnz .outputnow
		1281
		1282	test [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1529	hidnplayr	1283	jnz .ack_now
1514	hidnplayr	1284
1529	hidnplayr	1285	mov [ebx + SOCKET.lock], 0
		1286	call kernel_free
		1287	add esp, 4
		1288	ret
		1289
		1290	.ack_now:
		1291
		1292	DEBUGF 1,"ACK now!\n"
		1293
		1294	push ebx
		1295	mov eax, ebx
1514	hidnplayr	1296	call TCP_output
1529	hidnplayr	1297	pop ebx
1514	hidnplayr	1298
		1299	mov [ebx + SOCKET.lock], 0
1274	hidnplayr	1300	call kernel_free
1529	hidnplayr	1301	add esp, 4
		1302	ret
1274	hidnplayr	1303
1514	hidnplayr	1304	;------------------------------------------
		1305	; Generate an ACK, droping incoming segment
1274	hidnplayr	1306
1514	hidnplayr	1307	align 4
		1308	.drop_after_ack:
1274	hidnplayr	1309
1514	hidnplayr	1310	DEBUGF 1,"Drop after ACK\n"
1274	hidnplayr	1311
1514	hidnplayr	1312	test [edx + TCP_segment.Flags], TH_RST
		1313	jnz .drop
1274	hidnplayr	1314
1514	hidnplayr	1315	and [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1274	hidnplayr	1316
1529	hidnplayr	1317	push ebx
		1318	mov eax, ebx
1514	hidnplayr	1319	call TCP_output
1529	hidnplayr	1320	pop ebx
1318	hidnplayr	1321
1514	hidnplayr	1322	mov [ebx + SOCKET.lock], 0
		1323	call kernel_free
1529	hidnplayr	1324	add esp, 4
		1325	ret
1274	hidnplayr	1326
1514	hidnplayr	1327
		1328	;-------------------------------------------
		1329	; Generate an RST, dropping incoming segment
		1330
		1331	align 4
		1332	.drop_with_reset:
		1333
		1334	DEBUGF 1,"Drop with reset\n"
		1335
		1336	test [edx + TCP_segment.Flags], TH_RST
		1337	jnz .drop
		1338
		1339	;;; if its a multicast/broadcast, also drop
		1340
		1341	test [edx + TCP_segment.Flags], TH_ACK
		1342	jnz .respond_ack
		1343
		1344	test [edx + TCP_segment.Flags], TH_SYN
		1345	jnz .respond_syn
		1346
		1347	mov [ebx + SOCKET.lock], 0
		1348	call kernel_free
1529	hidnplayr	1349	add esp, 4
		1350	ret
1514	hidnplayr	1351
		1352	.respond_ack:
		1353
		1354	;;;;
		1355
1529	hidnplayr	1356	call TCP_respond_segment
1514	hidnplayr	1357
		1358	jmp .destroy_new_socket
		1359
		1360
		1361	.respond_syn:
		1362
		1363	;;;;
		1364
1529	hidnplayr	1365	call TCP_respond_segment
1514	hidnplayr	1366
		1367	jmp .destroy_new_socket
		1368
		1369	;-----
		1370	; Drop
		1371
		1372	align 4
		1373	.drop:
		1374
		1375	DEBUGF 1,"Dropping packet\n"
		1376
		1377	;;;; If debugging options are enabled, output the packet somwhere
		1378
		1379	.destroy_new_socket:
		1380
		1381	;;;; kill the newly created socket
		1382
		1383	mov [ebx + SOCKET.lock], 0
		1384	call kernel_free
1529	hidnplayr	1385	add esp, 4
		1386	ret
1514	hidnplayr	1387
		1388
		1389
		1390
		1391
		1392
		1393	;---------------------------
		1394	;
		1395	; TCP_pull_out_of_band
		1396	;
		1397	; IN: eax =
		1398	; ebx = socket ptr
		1399	; edx = tcp packet ptr
		1400	;
		1401	; OUT: /
		1402	;
		1403	;---------------------------
		1404
		1405	align 4
		1406	TCP_pull_out_of_band:
		1407
		1408	DEBUGF 1,"TCP_pull_out_of_band\n"
		1409
		1410	;;;; 1282-1305
		1411
1318	hidnplayr	1412	ret
		1413
		1414
		1415
		1416	;-----------------------------------------------------------------
		1417	;
1514	hidnplayr	1418	; TCP_output
1318	hidnplayr	1419	;
1519	hidnplayr	1420	; IN: eax = socket pointer
1514	hidnplayr	1421	;; esi = ptr to data
		1422	;; ecx = number of data bytes
		1423	;
1318	hidnplayr	1424	; OUT: /
		1425	;
		1426	;-----------------------------------------------------------------
		1427	align 4
1514	hidnplayr	1428	TCP_output:
1318	hidnplayr	1429
1514	hidnplayr	1430	DEBUGF 1,"TCP_output, socket: %x\n", eax
1318	hidnplayr	1431
1514	hidnplayr	1432	; We'll detect the length of the data to be transmitted, and flags to be used
		1433	; If there is some data, or any critical controls to send (SYN / RST), then transmit
		1434	; Otherwise, investigate further
1318	hidnplayr	1435
1514	hidnplayr	1436	mov ebx, [eax + TCP_SOCKET.SND_MAX]
		1437	cmp ebx, [eax + TCP_SOCKET.SND_UNA]
		1438	jne .not_idle
1318	hidnplayr	1439
1514	hidnplayr	1440	mov ebx, [eax + TCP_SOCKET.t_idle]
		1441	cmp ebx, [eax + TCP_SOCKET.t_rxtcur]
		1442	jle .not_idle
1318	hidnplayr	1443
1514	hidnplayr	1444	; We have been idle for a while and no ACKS are expected to clock out any data we send..
		1445	; Slow start to get ack "clock" running again.
1318	hidnplayr	1446
1514	hidnplayr	1447	mov ebx, [eax + TCP_SOCKET.t_maxseg]
		1448	mov [eax + TCP_SOCKET.SND_CWND], ebx
1318	hidnplayr	1449
1514	hidnplayr	1450	.not_idle:
		1451	.again:
		1452	mov ebx, [eax + TCP_SOCKET.SND_NXT] ; calculate offset
		1453	sub ebx, [eax + TCP_SOCKET.SND_UNA] ;
1318	hidnplayr	1454
1514	hidnplayr	1455	mov ecx, [eax + TCP_SOCKET.SND_WND] ; determine window
		1456	cmp ecx, [eax + TCP_SOCKET.SND_CWND] ;
		1457	jl @f ;
		1458	mov ecx, [eax + TCP_SOCKET.SND_CWND] ;
		1459	@@: ;
1318	hidnplayr	1460
1529	hidnplayr	1461	call TCP_outflags ; in dl
1318	hidnplayr	1462
1514	hidnplayr	1463	; If in persist timeout with window of 0, send 1 byte.
		1464	; Otherwise, if window is small but nonzero, and timer expired,
		1465	; we will send what we can and go to transmit state
1318	hidnplayr	1466
1514	hidnplayr	1467	test [eax + TCP_SOCKET.t_force], -1
		1468	jz .no_persist_timeout
1318	hidnplayr	1469
1514	hidnplayr	1470	test ecx, ecx
		1471	jnz .no_zero_window
1255	hidnplayr	1472
1529	hidnplayr	1473	cmp ebx, [eax + snd.size]
1514	hidnplayr	1474	jge @f
1255	hidnplayr	1475
1514	hidnplayr	1476	and dl, not (TH_FIN) ; clear the FIN flag ??? how can it be set before?
1255	hidnplayr	1477
1514	hidnplayr	1478	@@:
		1479	inc ecx
		1480	jmp .no_persist_timeout
1255	hidnplayr	1481
1514	hidnplayr	1482	.no_zero_window:
1254	hidnplayr	1483
1529	hidnplayr	1484	mov [eax + TCP_SOCKET.timer_persist], 0 ;;;;
1514	hidnplayr	1485	mov [eax + TCP_SOCKET.t_rxtshift], 0
1254	hidnplayr	1486
1514	hidnplayr	1487	.no_persist_timeout:
1159	hidnplayr	1488
1514	hidnplayr	1489	;;;106
1159	hidnplayr	1490
1529	hidnplayr	1491	mov esi, [eax + snd.size]
1514	hidnplayr	1492	cmp esi, ecx
		1493	jl @f
		1494	mov esi, ecx
		1495	@@:
		1496	sub esi, ebx
1254	hidnplayr	1497
1514	hidnplayr	1498	cmp esi, -1
		1499	jne .not_minus_one
1159	hidnplayr	1500
1514	hidnplayr	1501	; If FIN has been set, but not ACKed, and we havent been called to retransmit,
		1502	; len (esi) will be -1
		1503	; Otherwise, window shrank after we sent into it.
		1504	; If window shrank to 0, cancel pending retransmit and pull SND_NXT back to (closed) window
		1505	; We will enter persist state below.
		1506	; If window didn't close completely, just wait for an ACK
1159	hidnplayr	1507
1514	hidnplayr	1508	xor esi, esi
1159	hidnplayr	1509
1514	hidnplayr	1510	test ecx, ecx
		1511	jnz @f
1159	hidnplayr	1512
1529	hidnplayr	1513	mov [eax + TCP_SOCKET.timer_retransmission], 0 ; cancel retransmit
1274	hidnplayr	1514
1514	hidnplayr	1515	push [eax + TCP_SOCKET.SND_UNA]
		1516	pop [eax + TCP_SOCKET.SND_NXT]
		1517	@@:
1254	hidnplayr	1518
1514	hidnplayr	1519	.not_minus_one:
1254	hidnplayr	1520
1514	hidnplayr	1521	;;; 124
1159	hidnplayr	1522
1514	hidnplayr	1523	cmp esi, [eax + TCP_SOCKET.t_maxseg]
		1524	jle @f
1274	hidnplayr	1525
1514	hidnplayr	1526	mov esi, [eax + TCP_SOCKET.t_maxseg]
		1527	;sendalot = 1
1274	hidnplayr	1528
1514	hidnplayr	1529	@@:
1274	hidnplayr	1530
1514	hidnplayr	1531	;;; 128
1274	hidnplayr	1532
1514	hidnplayr	1533	mov edi, [eax + TCP_SOCKET.SND_NXT]
		1534	add edi, esi ; len
		1535	sub edi, [eax + TCP_SOCKET.SND_UNA]
1529	hidnplayr	1536	add edi, [eax + snd.size]
1514	hidnplayr	1537	cmp edi, 0
		1538	jle @f
1274	hidnplayr	1539
1514	hidnplayr	1540	and dl, not (TH_FIN) ; clear the FIN flag
1159	hidnplayr	1541
1514	hidnplayr	1542	@@:
1159	hidnplayr	1543
		1544
1529	hidnplayr	1545	; set ecx to space available in receive buffer
		1546	; From now on, ecx will be the window we advertise to the other end
1159	hidnplayr	1547
1529	hidnplayr	1548	mov ecx, SOCKET_MAXDATA
		1549	sub ecx, [eax + rcv.size]
1159	hidnplayr	1550
1514	hidnplayr	1551	;------------------------------
		1552	; Sender silly window avoidance
1159	hidnplayr	1553
1529	hidnplayr	1554	cmp ecx, [eax + TCP_SOCKET.t_maxseg]
1514	hidnplayr	1555	je .send
1274	hidnplayr	1556
1514	hidnplayr	1557	;;; TODO: 144-145
1274	hidnplayr	1558
1514	hidnplayr	1559	test [eax + TCP_SOCKET.t_force], -1
		1560	jnz .send
1274	hidnplayr	1561
1529	hidnplayr	1562	mov ebx, [eax + TCP_SOCKET.max_sndwnd]
		1563	shr ebx, 1
		1564	cmp ecx, ebx
		1565	jge .send
1274	hidnplayr	1566
1529	hidnplayr	1567	mov ebx, [eax + TCP_SOCKET.SND_NXT]
		1568	cmp ebx, [eax + TCP_SOCKET.SND_MAX]
		1569	jl .send
1254	hidnplayr	1570
1514	hidnplayr	1571	;----------------------------------------
		1572	; Check if a window update should be sent
1159	hidnplayr	1573
1529	hidnplayr	1574	test ecx, ecx ; window
		1575	jz .no_window
1159	hidnplayr	1576
1514	hidnplayr	1577	;;; TODO 154-172
1159	hidnplayr	1578
1514	hidnplayr	1579	.no_window:
1159	hidnplayr	1580
1514	hidnplayr	1581	;--------------------------
		1582	; Should a segment be sent?
1159	hidnplayr	1583
1514	hidnplayr	1584	test [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
		1585	jnz .send
1159	hidnplayr	1586
1514	hidnplayr	1587	test dl, TH_SYN + TH_RST
		1588	jnz .send
1159	hidnplayr	1589
1514	hidnplayr	1590	mov eax, [ebx + TCP_SOCKET.SND_UP]
		1591	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
		1592	jg .send
1249	hidnplayr	1593
1514	hidnplayr	1594	test dl, TH_FIN
		1595	jz .enter_persist
1318	hidnplayr	1596
1514	hidnplayr	1597	test [ebx + TCP_SOCKET.t_flags], TF_SENTFIN
		1598	jnz .send
1254	hidnplayr	1599
1514	hidnplayr	1600	mov eax, [ebx + TCP_SOCKET.SND_NXT]
		1601	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
		1602	je .send
1254	hidnplayr	1603
1514	hidnplayr	1604	;--------------------
		1605	; Enter persist state
1318	hidnplayr	1606
1514	hidnplayr	1607	.enter_persist:
1318	hidnplayr	1608
1519	hidnplayr	1609	DEBUGF 1,"Entering persist state\n"
1318	hidnplayr	1610
1514	hidnplayr	1611	;--------------------------------------
		1612	; No reason to send a segment, just ret
1318	hidnplayr	1613
1514	hidnplayr	1614	DEBUGF 1,"No reason to send a segment\n"
1318	hidnplayr	1615
1514	hidnplayr	1616	ret
1318	hidnplayr	1617
		1618
1514	hidnplayr	1619	;-----------------------------------------------
		1620	;
		1621	; Send a segment
		1622	;
1529	hidnplayr	1623	; eax = socket pointer
1514	hidnplayr	1624	; dl = flags
		1625	;
		1626	;-----------------------------------------------
1318	hidnplayr	1627
1529	hidnplayr	1628	.send:
1318	hidnplayr	1629
1514	hidnplayr	1630	DEBUGF 1,"Preparing to send a segment\n"
1318	hidnplayr	1631
1529	hidnplayr	1632	mov edi, TCP_segment.Data ; edi will contain headersize
1318	hidnplayr	1633
1529	hidnplayr	1634	sub esp, 8 ; create some space on stack
		1635	push eax ; save this too..
		1636
1514	hidnplayr	1637	;------------------------------------
		1638	; Send options with first SYN segment
1318	hidnplayr	1639
1514	hidnplayr	1640	test dl, TH_SYN
		1641	jz .no_options
1318	hidnplayr	1642
1529	hidnplayr	1643	push [eax + TCP_SOCKET.ISS]
		1644	pop [eax + TCP_SOCKET.SND_NXT]
1318	hidnplayr	1645
1529	hidnplayr	1646	test [eax + TCP_SOCKET.t_flags], TF_NOOPT
1514	hidnplayr	1647	jnz .no_options
1318	hidnplayr	1648
1529	hidnplayr	1649	mov ecx, 1460
		1650	or ecx, TCP_OPT_MAXSEG shl 24 + 4 shl 16
		1651	bswap ecx
		1652	push ecx
		1653	add di, 4
1514	hidnplayr	1654
1529	hidnplayr	1655	test [eax + TCP_SOCKET.t_flags], TF_REQ_SCALE
1514	hidnplayr	1656	jz .no_syn
		1657
		1658	test dl, TH_ACK
		1659	jnz .scale_opt
		1660
1529	hidnplayr	1661	test [eax + TCP_SOCKET.t_flags], TF_RCVD_SCALE
1514	hidnplayr	1662	jz .no_syn
		1663
		1664	.scale_opt:
1529	hidnplayr	1665	movzx ecx, byte [eax + TCP_SOCKET.request_r_scale]
		1666	or ecx, TCP_OPT_WINDOW shl 24 + 4 shl 16 + TCP_OPT_NOP shl 8
		1667	bswap ecx
		1668	pushd ecx
1514	hidnplayr	1669	add di, 4
1159	hidnplayr	1670
1514	hidnplayr	1671	.no_syn:
1159	hidnplayr	1672
1514	hidnplayr	1673	;------------------------------------
		1674	; Make the timestamp option if needed
1159	hidnplayr	1675
1529	hidnplayr	1676	test [eax + TCP_SOCKET.t_flags], TF_REQ_TSTMP
1514	hidnplayr	1677	jz .no_timestamp
1159	hidnplayr	1678
1514	hidnplayr	1679	test dl, TH_RST
		1680	jnz .no_timestamp
		1681
		1682	test dl, TH_ACK
		1683	jz .timestamp
		1684
1529	hidnplayr	1685	test [eax + TCP_SOCKET.t_flags], TF_RCVD_TSTMP
1514	hidnplayr	1686	jz .no_timestamp
		1687
		1688	.timestamp:
1529	hidnplayr	1689	mov esi, [timer_ticks]
		1690	bswap esi
		1691	push esi
1514	hidnplayr	1692	pushw 0
1529	hidnplayr	1693	pushd TCP_OPT_TIMESTAMP + 10 shl 8 + TCP_OPT_NOP shl 16 + TCP_OPT_NOP shl 24
1514	hidnplayr	1694	add di, 10
		1695
		1696	.no_timestamp:
		1697	;; TODO: check if we dont exceed the max segment size
		1698
		1699	.no_options:
1529	hidnplayr	1700	; eax = socket ptr
		1701	; edx = flags
		1702	; ecx = data size
		1703	; edi = header size
		1704	; esi = snd ring buff ptr
1514	hidnplayr	1705
1529	hidnplayr	1706	xor ecx, ecx ;;;;;
1514	hidnplayr	1707	add ecx, edi ; total TCP segment size
		1708
1529	hidnplayr	1709	; Start by pushing all TCP header values in reverse order on stack
		1710	; (essentially, creating the tcp header!)
1514	hidnplayr	1711
1529	hidnplayr	1712	pushw 0 ; .UrgentPointer dw ?
		1713	pushw 0 ; .Checksum dw ?
		1714	pushw 0x00a0 ; .Window dw ? ;;;;;;;
		1715	shl edi, 2 ; .DataOffset db ? only 4 left-most bits
		1716	shl dx, 8
		1717	or dx, di ; .Flags db ?
		1718	pushw dx
		1719	shr edi, 2 ; .DataOffset db ? ;;;;
1514	hidnplayr	1720
1529	hidnplayr	1721	push [eax + TCP_SOCKET.RCV_NXT] ; .AckNumber dd ?
		1722	ntohld [esp]
1159	hidnplayr	1723
1529	hidnplayr	1724	push [eax + TCP_SOCKET.SND_NXT] ; .SequenceNumber dd ?
		1725	ntohld [esp]
1159	hidnplayr	1726
1529	hidnplayr	1727	push [eax + TCP_SOCKET.RemotePort] ; .DestinationPort dw ?
		1728	ntohlw [esp]
1249	hidnplayr	1729
1529	hidnplayr	1730	push [eax + TCP_SOCKET.LocalPort] ; .SourcePort dw ?
		1731	ntohlw [esp]
1274	hidnplayr	1732
1529	hidnplayr	1733	push edi ; header size
1274	hidnplayr	1734
1529	hidnplayr	1735	; Create the IP packet
		1736	mov ebx, [eax + IP_SOCKET.LocalIP] ; source ip
		1737	mov eax, [eax + IP_SOCKET.RemoteIP] ; dest ip
		1738	; mov ecx, ; data length
		1739	; mov dx, ; fragment id
		1740	mov di, IP_PROTO_TCP shl 8 + 128
		1741	call IPv4_output
		1742	jz .fail
1274	hidnplayr	1743
1529	hidnplayr	1744	;-----------------------------------------
		1745	; Move TCP header from stack to TCP packet
1274	hidnplayr	1746
1529	hidnplayr	1747	; pop ecx ; header size
		1748	; mov esi, esp
		1749	; add esp, ecx
		1750	; shr ecx, 2
		1751	; rep movsd
1274	hidnplayr	1752
1529	hidnplayr	1753	mov ecx, [esp]
		1754	lea esi, [esp+4]
		1755	shr ecx, 2
		1756	rep movsd
1274	hidnplayr	1757
1529	hidnplayr	1758	pop ecx
		1759	add esp, ecx
1254	hidnplayr	1760
1529	hidnplayr	1761	mov [esp + 3*4+4], edx ; packet size
		1762	mov [esp + 3*4], eax ; packet ptr
1254	hidnplayr	1763
1529	hidnplayr	1764	mov edx, edi
		1765	sub edx, ecx
1159	hidnplayr	1766
1514	hidnplayr	1767	;--------------
		1768	; Copy the data
1159	hidnplayr	1769
1529	hidnplayr	1770	; eax = ptr to ring struct
		1771	; ecx = buffer size
		1772	; edi = ptr to buffer
1249	hidnplayr	1773
1529	hidnplayr	1774	mov eax, [esp] ; socket ptr
		1775	push ecx edx
		1776	add eax, snd
		1777	call SOCKET_ring_read
		1778	pop esi ecx
		1779	pop eax
1254	hidnplayr	1780
1529	hidnplayr	1781	;-------------------------------------------------------------
		1782	; Create the checksum (we have already pushed IPs onto stack)
1254	hidnplayr	1783
1529	hidnplayr	1784	DEBUGF 1,"checksum: ptr=%x size=%u\n", esi, ecx
		1785	DEBUGF 1,"ip=%x\n", [esp]:8
		1786	DEBUGF 1,"ip=%x\n", [esp+4]:8
1159	hidnplayr	1787
1529	hidnplayr	1788	TCP_checksum (eax + IP_SOCKET.LocalIP), (eax + IP_SOCKET.RemoteIP)
		1789	mov [esi+TCP_segment.Checksum], dx
		1790
1514	hidnplayr	1791	;----------------
		1792	; Send the packet
1159	hidnplayr	1793
1529	hidnplayr	1794	DEBUGF 1,"Sending TCP Packet to device %x\n", ebx
		1795	call [ebx + NET_DEVICE.transmit]
		1796	ret
1159	hidnplayr	1797
1514	hidnplayr	1798
1529	hidnplayr	1799	.fail:
		1800	pop ecx
		1801	add esp, ecx
		1802	add esp, 4+4+8+4
		1803	DEBUGF 1,"TCP_output: failed\n"
1159	hidnplayr	1804	ret
		1805
1529	hidnplayr	1806
		1807
1514	hidnplayr	1808	;-------------------------
		1809	;
		1810	; TCP_outflags
		1811	;
		1812	; IN: eax = socket ptr
		1813	;
		1814	; OUT: edx = flags
		1815	;
		1816	;-------------------------
1249	hidnplayr	1817	align 4
1514	hidnplayr	1818	TCP_outflags:
1254	hidnplayr	1819
1514	hidnplayr	1820	mov edx, [eax + TCP_SOCKET.t_state]
		1821	movzx edx, byte [edx + .flaglist]
1254	hidnplayr	1822
1514	hidnplayr	1823	DEBUGF 1,"TCP_outflags, socket: %x, flags: %x\n", eax, dl
		1824
1159	hidnplayr	1825	ret
		1826
1514	hidnplayr	1827	.flaglist:
1159	hidnplayr	1828
1514	hidnplayr	1829	db TH_RST + TH_ACK ; TCB_CLOSED
		1830	db 0 ; TCB_LISTEN
		1831	db TH_SYN ; TCB_SYN_SENT
		1832	db TH_SYN + TH_ACK ; TCB_SYN_RECEIVED
		1833	db TH_ACK ; TCB_ESTABLISHED
		1834	db TH_ACK ; TCB_CLOSE_WAIT
		1835	db TH_SYN + TH_ACK ; TCB_FIN_WAIT_1
		1836	db TH_SYN + TH_ACK ; TCB_CLOSING
		1837	db TH_SYN + TH_ACK ; TCB_LAST_ACK
		1838	db TH_ACK ; TCB_FIN_WAIT_2
		1839	db TH_ACK ; TCB_TIMED_WAIT
1249	hidnplayr	1840
1514	hidnplayr	1841
1529	hidnplayr	1842
		1843
1514	hidnplayr	1844	;-------------------------
		1845	;
		1846	; TCP_drop
		1847	;
		1848	; IN: eax = socket ptr
		1849	;
		1850	; OUT: /
		1851	;
		1852	;-------------------------
1249	hidnplayr	1853	align 4
1514	hidnplayr	1854	TCP_drop:
1254	hidnplayr	1855
1514	hidnplayr	1856	DEBUGF 1,"TCP_drop\n"
1254	hidnplayr	1857
1514	hidnplayr	1858	; cmp [eax + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		1859	; jl .no_syn_received
1159	hidnplayr	1860
1514	hidnplayr	1861	mov [eax + TCP_SOCKET.t_state], TCB_CLOSED
1159	hidnplayr	1862
1514	hidnplayr	1863	call TCP_output
1254	hidnplayr	1864
1514	hidnplayr	1865	; .no_syn_received:
		1866
1159	hidnplayr	1867	ret
		1868
		1869
1254	hidnplayr	1870
		1871
1159	hidnplayr	1872
1514	hidnplayr	1873	;---------------------------------------
		1874	;
1519	hidnplayr	1875	; The easy way to send an ACK/RST/keepalive segment
1514	hidnplayr	1876	;
1529	hidnplayr	1877	; TCP_respond_socket:
		1878	;
		1879	; IN: ebx = socket ptr
1519	hidnplayr	1880	; cl = flags
1514	hidnplayr	1881	;
1529	hidnplayr	1882	;--------------------------------------
1514	hidnplayr	1883	align 4
1529	hidnplayr	1884	TCP_respond_socket:
1254	hidnplayr	1885
1529	hidnplayr	1886	DEBUGF 1,"TCP_respond_socket\n"
1159	hidnplayr	1887
1519	hidnplayr	1888	;---------------------
		1889	; Create the IP packet
		1890
1529	hidnplayr	1891	push cx ebx
		1892	mov eax, [ebx + IP_SOCKET.RemoteIP]
		1893	mov ebx, [ebx + IP_SOCKET.LocalIP]
1519	hidnplayr	1894	mov ecx, TCP_segment.Data
1529	hidnplayr	1895	mov di , IP_PROTO_TCP shl 8 + 128
		1896	call IPv4_output
1519	hidnplayr	1897	test edi, edi
		1898	jz .error
1529	hidnplayr	1899	pop esi cx
		1900	push edx eax
1519	hidnplayr	1901
1529	hidnplayr	1902	;-----------------------------------------------
		1903	; Fill in the TCP header by using the socket ptr
1519	hidnplayr	1904
1529	hidnplayr	1905	mov ax, [esi + TCP_SOCKET.LocalPort]
		1906	rol ax, 8
		1907	stosw
		1908	mov ax, [esi + TCP_SOCKET.RemotePort]
		1909	rol ax, 8
		1910	stosw
		1911	mov eax, [esi + TCP_SOCKET.SND_NXT]
		1912	bswap eax
		1913	stosd
		1914	mov eax, [esi + TCP_SOCKET.RCV_NXT]
		1915	bswap eax
		1916	stosd
		1917	mov al, 0x50 ; Dataoffset: 20 bytes
		1918	stosb
		1919	mov al, cl
		1920	stosb
		1921	mov ax, [esi + TCP_SOCKET.RCV_WND]
		1922	rol ax, 8
		1923	stosw ; window
		1924	xor eax, eax
		1925	stosd ; checksum + urgentpointer
1519	hidnplayr	1926
		1927	;---------------------
		1928	; Fill in the checksum
		1929
		1930	.checksum:
1529	hidnplayr	1931	sub edi, TCP_segment.Data
		1932	mov ecx, TCP_segment.Data
		1933	xchg esi, edi
		1934	TCP_checksum (edi + IP_SOCKET.LocalIP), (esi + IP_SOCKET.RemoteIP)
		1935	mov [esi+TCP_segment.Checksum], dx
1519	hidnplayr	1936
		1937	;--------------------
		1938	; And send the segment
		1939
		1940	call [ebx + NET_DEVICE.transmit]
1159	hidnplayr	1941	ret
		1942
1519	hidnplayr	1943	.error:
1529	hidnplayr	1944	DEBUGF 1,"TCP_respond failed\n"
		1945	add esp, 2+4
1159	hidnplayr	1946
1519	hidnplayr	1947	ret
1514	hidnplayr	1948
1529	hidnplayr	1949
		1950
		1951	;-------------------------
		1952	; TCP_respond.segment:
		1953	;
		1954	; IN: edx = segment ptr (a previously received segment)
		1955	; cl = flags
		1956
		1957	align 4
		1958	TCP_respond_segment:
		1959
		1960	DEBUGF 1,"TCP_respond_segment\n"
		1961
		1962	;---------------------
		1963	; Create the IP packet
		1964
		1965	push cx edx
		1966	mov ebx, [edx - 20 + IPv4_Packet.SourceAddress] ;;;; and what if ip packet had options?!
		1967	mov eax, [edx - 20 + IPv4_Packet.DestinationAddress] ;;;
		1968	mov ecx, TCP_segment.Data
		1969	mov di , IP_PROTO_TCP shl 8 + 128
		1970	call IPv4_output
		1971	test edi, edi
		1972	jz .error
		1973
		1974	pop esi cx
		1975	push edx eax
		1976
1519	hidnplayr	1977	;---------------------------------------------------
		1978	; Fill in the TCP header by using a received segment
		1979
		1980	mov ax, [esi + TCP_segment.DestinationPort]
		1981	rol ax, 8
		1982	stosw
		1983	mov ax, [esi + TCP_segment.SourcePort]
		1984	rol ax, 8
		1985	stosw
		1986	mov eax, [esi + TCP_segment.AckNumber]
		1987	bswap eax
		1988	stosd
		1989	xor eax, eax
		1990	stosd
		1991	mov al, 0x50 ; Dataoffset: 20 bytes
		1992	stosb
		1993	mov al, cl
		1994	stosb
		1995	mov ax, 1280
		1996	rol ax, 8
		1997	stosw ; window
		1998	xor eax, eax
		1999	stosd ; checksum + urgentpointer
		2000
1529	hidnplayr	2001	;---------------------
		2002	; Fill in the checksum
1519	hidnplayr	2003
1529	hidnplayr	2004	.checksum:
		2005	lea esi, [edi - TCP_segment.Data]
		2006	mov ecx, TCP_segment.Data
		2007	TCP_checksum (esi - 20 + IPv4_Packet.DestinationAddress), (esi - 20 + IPv4_Packet.DestinationAddress)
		2008	mov [esi+TCP_segment.Checksum], dx
1519	hidnplayr	2009
1529	hidnplayr	2010	;--------------------
		2011	; And send the segment
1519	hidnplayr	2012
1529	hidnplayr	2013	call [ebx + NET_DEVICE.transmit]
		2014	ret
1519	hidnplayr	2015
1529	hidnplayr	2016	.error:
		2017	DEBUGF 1,"TCP_respond failed\n"
		2018	add esp, 2+4
1519	hidnplayr	2019
		2020	ret
		2021
		2022
		2023
1254	hidnplayr	2024
		2025	;---------------------------------------------------------------------------
		2026	;
		2027	; TCP_API
		2028	;
		2029	; This function is called by system function 75
		2030	;
		2031	; IN: subfunction number in bl
		2032	; device number in bh
		2033	; ecx, edx, .. depends on subfunction
		2034	;
		2035	; OUT:
		2036	;
		2037	;---------------------------------------------------------------------------
		2038	align 4
		2039	TCP_API:
		2040
		2041	movzx eax, bh
		2042	shl eax, 2
		2043
		2044	test bl, bl
		2045	jz .packets_tx ; 0
		2046	dec bl
		2047	jz .packets_rx ; 1
		2048
		2049	.error:
		2050	mov eax, -1
		2051	ret
		2052
		2053	.packets_tx:
1514	hidnplayr	2054	add eax, TCP_segments_tx
1254	hidnplayr	2055	mov eax, [eax]
		2056	ret
		2057
		2058	.packets_rx:
1514	hidnplayr	2059	add eax, TCP_segments_rx
1254	hidnplayr	2060	mov eax, [eax]
		2061	ret

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(root)/kernel/branches/net/network/tcp.inc – Rev 1529