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: 1530 $
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
1530	hidnplayr	243	add dl, byte [IP1+1]
		244	adc dh, byte [IP1+0]
		245	adc dl, byte [IP1+3]
		246	adc dh, byte [IP1+2]
1529	hidnplayr	247
		248	; destination address
1530	hidnplayr	249	adc dl, byte [IP2+1]
		250	adc dh, byte [IP2+0]
		251	adc dl, byte [IP2+3]
		252	adc dh, byte [IP2+2]
1529	hidnplayr	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
1530	hidnplayr	309	TCP_checksum (esp), (esp+4)
1529	hidnplayr	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
1530	hidnplayr	440	cmp [ebx + TCP_SOCKET.t_state], TCB_LISTEN ; no options when in listen state
1529	hidnplayr	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
1530	hidnplayr	478	movzx eax, word[edi+2]
		479	rol ax, 8
		480	DEBUGF 1,"Maxseg: %u", ax
1529	hidnplayr	481
1530	hidnplayr	482	mov [ebx + TCP_SOCKET.t_maxseg], eax
		483
1529	hidnplayr	484	@@:
		485	add edi, 4
		486	jmp .opt_loop
		487
		488
		489	.opt_window:
		490	cmp byte [edi+1], 3
		491	jne .no_options
		492
		493	test [edx + TCP_segment.Flags], TH_SYN
		494	jz @f
		495
		496	DEBUGF 1,"Got window option"
		497
		498	;;;;;
		499	@@:
		500	add edi, 3
		501	jmp .opt_loop
		502
		503
		504	.opt_timestamp:
		505	cmp byte [edi+1], 10
		506	jne .no_options
		507
		508	DEBUGF 1,"Got timestamp option"
		509
		510	;;;;;
		511
		512	add edi, 10
		513	jmp .opt_loop
		514
		515	.no_options:
		516
1514	hidnplayr	517	;-----------------------------------------------------------------------
		518	; Time to do some header prediction (Original Principle by Van Jacobson)
		519
		520	; There are two common cases for an uni-directional data transfer.
		521	;
		522	; General rule: the packets has no control flags, is in-sequence,
		523	; window width didnt change and we're not retransmitting.
		524	;
		525	; Second rules:
		526	; - If the length is 0 and the ACK moved forward, we're the sender side of the transfer.
		527	; In this case we'll free the ACK'ed data and notify higher levels that we have free space in buffer
		528	;
		529	; - If the length is not 0 and the ACK didn't move, we're the receiver side of the transfer.
		530	; If the packets are in order (data queue is empty), add the data to the socket buffer and request a delayed ACK
		531
1529	hidnplayr	532	cmp [ebx + TCP_SOCKET.t_state], TCB_ESTABLISHED
1514	hidnplayr	533	jnz .not_uni_xfer
		534
1529	hidnplayr	535	test [edx + TCP_segment.Flags], TH_SYN + TH_FIN + TH_RST + TH_URG
1514	hidnplayr	536	jnz .not_uni_xfer
		537
1529	hidnplayr	538	test [edx + TCP_segment.Flags], TH_ACK
1514	hidnplayr	539	jz .not_uni_xfer
		540
		541	mov eax, [edx + TCP_segment.SequenceNumber]
		542	cmp eax, [ebx + TCP_SOCKET.RCV_NXT]
		543	jne .not_uni_xfer
		544
1529	hidnplayr	545	movzx eax, [edx + TCP_segment.Window] ;;;;; (should use pre-calculated value isntead: todo: figure out where to store it)
1514	hidnplayr	546	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		547	jne .not_uni_xfer
		548
		549	mov eax, [ebx + TCP_SOCKET.SND_NXT]
		550	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		551	jne .not_uni_xfer
		552
		553	;---------------------------------------
		554	; check if we are sender in the uni-xfer
		555
		556	; If the following 4 conditions are all true, this segment is a pure ACK.
		557	;
1529	hidnplayr	558	; - The segment contains no data.
		559	test ecx, ecx
1514	hidnplayr	560	jnz .not_sender
1274	hidnplayr	561
1529	hidnplayr	562	; - The congestion window is greater than or equal to the current send window.
1514	hidnplayr	563	; 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.
		564	mov eax, [ebx + TCP_SOCKET.SND_CWND]
		565	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		566	jl .not_uni_xfer
1318	hidnplayr	567
1529	hidnplayr	568	; - The acknowledgment field in the segment is less than or equal to the maximum sequence number sent.
		569	mov ecx, [edx + TCP_segment.AckNumber]
		570	cmp ecx, [ebx + TCP_SOCKET.SND_MAX]
		571	jg .not_uni_xfer
		572
		573	; - The acknowledgment field in the segment is greater than the largest unacknowledged sequence number.
		574	sub ecx, [ebx + TCP_SOCKET.SND_UNA]
		575	jle .not_uni_xfer
		576
1514	hidnplayr	577	DEBUGF 1,"Header prediction: we are sender\n"
1274	hidnplayr	578
1514	hidnplayr	579	;---------------------------------
		580	; Packet is a pure ACK, process it
1274	hidnplayr	581
1514	hidnplayr	582	; Update RTT estimators
1159	hidnplayr	583
1514	hidnplayr	584	; Delete acknowledged bytes from send buffer
1529	hidnplayr	585	; notice how ecx already holds number of bytes ack-ed
1254	hidnplayr	586
1529	hidnplayr	587	lea eax, [ebx + snd]
		588	call SOCKET_ring_free
		589
1514	hidnplayr	590	; Stop retransmit timer
1519	hidnplayr	591	mov [ebx + TCP_SOCKET.timer_ack], 0
1159	hidnplayr	592
1514	hidnplayr	593	; Awaken waiting processes
1519	hidnplayr	594	mov eax, ebx
		595	call SOCKET_notify_owner
1318	hidnplayr	596
1514	hidnplayr	597	; Generate more output
1519	hidnplayr	598	call TCP_output
1254	hidnplayr	599
1514	hidnplayr	600	jmp .drop
1159	hidnplayr	601
1514	hidnplayr	602	;-------------------------------------------------
		603	; maybe we are the receiver in the uni-xfer then..
		604
		605	.not_sender:
1529	hidnplayr	606	; - The amount of data in the segment is greater than 0 (data count is in ecx)
1514	hidnplayr	607
1529	hidnplayr	608	; - The acknowledgment field equals the largest unacknowledged sequence number. This means no data is acknowledged by this segment.
1514	hidnplayr	609	mov eax, [edx + TCP_segment.AckNumber]
		610	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
		611	jne .not_uni_xfer
		612
1529	hidnplayr	613	; - The reassembly list of out-of-order segments for the connection is empty (seg_next equals tp). ;;;;;;;
1514	hidnplayr	614
		615	jnz .not_uni_xfer
		616
		617	;-------------------------------------
		618	; Complete processing of received data
		619
		620	DEBUGF 1,"header prediction: we are receiver\nreceiving %u bytes of data\n", ecx
		621
1529	hidnplayr	622	add esi, edx
		623	lea eax, [ebx + rcv]
		624	call SOCKET_ring_add ; Add the data to the socket buffer
1514	hidnplayr	625
1529	hidnplayr	626	add [ebx + TCP_SOCKET.RCV_NXT], ecx ; Update sequence number with number of bytes we have copied
		627	or [ebx + TCP_SOCKET.t_flags], TF_DELACK ; Set delayed ack flag
1514	hidnplayr	628
		629	jmp .drop
		630
		631	;----------------------------------------------------
1529	hidnplayr	632	; Header prediction failed, doing it the slow way.. ;;;;; current implementation of header prediction destroys some regs (ecx) !!
1514	hidnplayr	633
		634	.not_uni_xfer:
		635
		636	DEBUGF 1,"Header prediction failed\n"
		637
		638	;------------------------------
		639	; Calculate receive window size
		640
		641	;;;;
		642
		643	;-------------------------
		644	; TCP slow input procedure
		645
		646	DEBUGF 1,"TCP slow input procedure\n"
		647
1529	hidnplayr	648	cmp [ebx + TCP_SOCKET.t_state], TCB_LISTEN
1514	hidnplayr	649	je .LISTEN
		650
1529	hidnplayr	651	cmp [ebx + TCP_SOCKET.t_state], TCB_SYN_SENT
1514	hidnplayr	652	je .SYN_SENT
		653
		654	;--------------------------------------------
		655	; Protection Against Wrapped Sequence Numbers
		656
		657	; First, check timestamp if present
		658
		659	;;;; TODO
		660
		661	; Then, check if at least some bytes of data are within window
		662
		663	;;;; TODO
		664
		665	jmp .trim_then_step6
		666
1529	hidnplayr	667	;-------------
		668	; Passive Open
		669
1249	hidnplayr	670	align 4
1514	hidnplayr	671	.LISTEN:
1196	hidnplayr	672
1514	hidnplayr	673	DEBUGF 1,"TCP state: listen\n"
1159	hidnplayr	674
1514	hidnplayr	675	test [edx + TCP_segment.Flags], TH_RST
		676	jnz .drop
1159	hidnplayr	677
1514	hidnplayr	678	test [edx + TCP_segment.Flags], TH_ACK
		679	jnz .drop_with_reset
1159	hidnplayr	680
1514	hidnplayr	681	test [edx + TCP_segment.Flags], TH_SYN
		682	jz .drop
1159	hidnplayr	683
1529	hidnplayr	684	; TODO: find sender ip address somewhere!
1514	hidnplayr	685	; TODO: check if it's a broadcast or multicast, and drop if so
1159	hidnplayr	686
1529	hidnplayr	687	call SOCKET_fork
		688	jz .drop ; if we could not open a new connection, drop segment (;;;; should we send RST too?)
1514	hidnplayr	689
1529	hidnplayr	690	;-----------------------
		691	; Fill in some variables
1514	hidnplayr	692
1529	hidnplayr	693	add [TCP_sequence_num], 64000
1514	hidnplayr	694
1529	hidnplayr	695	push [edx + TCP_segment.SourcePort]
		696	pop [eax + TCP_SOCKET.RemotePort]
1514	hidnplayr	697
1529	hidnplayr	698	push [edx + TCP_segment.SequenceNumber]
		699	pop [eax + TCP_SOCKET.IRS]
1159	hidnplayr	700
1529	hidnplayr	701	push [eax + TCP_SOCKET.ISS]
		702	pop [eax + TCP_SOCKET.SND_NXT]
1159	hidnplayr	703
1529	hidnplayr	704	mov [eax + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		705	mov [eax + TCP_SOCKET.t_flags], TF_ACKNOW
		706	mov [eax + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval
1159	hidnplayr	707
1529	hidnplayr	708	mov ebx, eax
1159	hidnplayr	709
1514	hidnplayr	710	jmp .trim_then_step6
1159	hidnplayr	711
1254	hidnplayr	712
1529	hidnplayr	713	;------------
		714	; Active Open
1159	hidnplayr	715
1514	hidnplayr	716	align 4
		717	.SYN_SENT:
1281	hidnplayr	718
1514	hidnplayr	719	DEBUGF 1,"TCP state: syn_sent\n"
1159	hidnplayr	720
1514	hidnplayr	721	test [edx + TCP_segment.Flags], TH_ACK
		722	jz @f
1281	hidnplayr	723
1514	hidnplayr	724	mov eax, [edx + TCP_segment.AckNumber]
		725	cmp eax, [ebx + TCP_SOCKET.ISS]
		726	jle .drop_with_reset
1281	hidnplayr	727
1529	hidnplayr	728	DEBUGF 1,"snd_max = %x\n", [ebx + TCP_SOCKET.SND_MAX] ;;; TODO: set this, but where?
		729
		730	; mov eax, [edx + TCP_segment.AckNumber]
		731	;; cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		732	;; jg .drop_with_reset
1514	hidnplayr	733	@@:
1281	hidnplayr	734
1514	hidnplayr	735	test [edx + TCP_segment.Flags], TH_RST
		736	jz @f
1281	hidnplayr	737
1514	hidnplayr	738	test [edx + TCP_segment.Flags], TH_ACK
		739	jz .drop
1281	hidnplayr	740
1514	hidnplayr	741	;tp = tcp_drop(tp, ECONNREFUSED)
1159	hidnplayr	742
1514	hidnplayr	743	jmp .drop
		744	@@:
1159	hidnplayr	745
1514	hidnplayr	746	test [edx + TCP_segment.Flags], TH_SYN
		747	jz .drop
1318	hidnplayr	748
1529	hidnplayr	749	; at this point, segment seems to be valid
		750
1514	hidnplayr	751	test [edx + TCP_segment.Flags], TH_ACK
1529	hidnplayr	752	jz .no_syn_ack
1514	hidnplayr	753
1529	hidnplayr	754	; now, process received SYN in response to an active open
		755
1514	hidnplayr	756	mov eax, [edx + TCP_segment.AckNumber]
		757	mov [ebx + TCP_SOCKET.SND_UNA], eax
		758	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		759	jle @f
		760	mov [ebx + TCP_SOCKET.SND_NXT], eax
1529	hidnplayr	761	@@:
1514	hidnplayr	762
1529	hidnplayr	763	.no_syn_ack:
1514	hidnplayr	764
1529	hidnplayr	765	mov [ebx + TCP_SOCKET.timer_retransmission], 0 ; disable retransmission
1514	hidnplayr	766
1529	hidnplayr	767	push [edx + TCP_segment.SequenceNumber]
		768	pop [ebx + TCP_SOCKET.IRS]
		769
		770	;;; TODO: tcp_rcvseqinit
		771
		772	mov [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
		773
		774	mov eax, [ebx + TCP_SOCKET.SND_UNA]
		775	cmp eax, [ebx + TCP_SOCKET.ISS]
		776	jle .simultaneous_open
		777
		778	test [edx + TCP_segment.Flags], TH_ACK
		779	jz .simultaneous_open
		780
		781	DEBUGF 1,"TCP: active open\n"
		782
		783	; TODO: update stats
1514	hidnplayr	784	; TODO: set socket state to connected
		785
		786	mov [ebx + TCP_SOCKET.t_state], TCB_ESTABLISHED
		787
		788	; TODO: check if we should scale the connection (567-572)
		789	; TODO: update RTT estimators
		790
1529	hidnplayr	791	jmp .trimthenstep6
1514	hidnplayr	792
1529	hidnplayr	793	.simultaneous_open:
1514	hidnplayr	794
1529	hidnplayr	795	DEBUGF 1,"TCP: simultaneous open\n"
1514	hidnplayr	796	; We have received a syn but no ACK, so we are having a simultaneous open..
		797	mov [ebx + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		798
		799	;-------------------------------------
		800	; Common processing for receipt of SYN
		801
		802	.trimthenstep6:
		803
		804	inc [edx + TCP_segment.SequenceNumber]
		805
		806	cmp cx, [ebx + TCP_SOCKET.RCV_WND]
		807	jle @f
		808
		809	movzx eax, cx
		810	sub ax, [ebx + TCP_SOCKET.RCV_WND]
		811	; TODO: 592
		812	mov cx, [ebx + TCP_SOCKET.RCV_WND]
		813	; TODO...
		814	@@:
		815	;;;;;
1529	hidnplayr	816	jmp .step6
1514	hidnplayr	817
		818
		819
		820
		821
1529	hidnplayr	822	.trim_then_step6:
1159	hidnplayr	823
1529	hidnplayr	824	DEBUGF 1,"Trimming window\n"
1159	hidnplayr	825
1514	hidnplayr	826	;----------------------------
		827	; trim any data not in window
1159	hidnplayr	828
1514	hidnplayr	829	mov eax, [ebx + TCP_SOCKET.RCV_NXT]
		830	sub eax, [edx + TCP_segment.SequenceNumber]
1318	hidnplayr	831
1514	hidnplayr	832	test eax, eax
		833	jz .no_drop
1274	hidnplayr	834
1514	hidnplayr	835	test [edx + TCP_segment.Flags], TH_SYN
		836	jz .no_drop
		837
		838	and [edx + TCP_segment.Flags], not (TH_SYN)
		839	inc [edx + TCP_segment.SequenceNumber]
		840
		841	cmp [edx + TCP_segment.UrgentPointer], 1
		842	jl @f
		843
		844	dec [edx + TCP_segment.UrgentPointer]
		845
		846	jmp .no_drop
		847	@@:
		848
		849	and [edx + TCP_segment.Flags], not (TH_URG)
		850	dec eax
		851
		852	.no_drop:
		853
1529	hidnplayr	854	DEBUGF 1,"Going to drop %u bytes of data", eax
		855
1514	hidnplayr	856	; eax holds number of bytes to drop
		857
		858	;----------------------------------
		859	; Check for entire duplicate packet
		860
		861	cmp eax, ecx
		862	jge .duplicate
		863
		864	;;; TODO: figure 28.30
		865
		866	;------------------------
		867	; Check for duplicate FIN
		868
		869	test [edx + TCP_segment.Flags], TH_FIN
		870	jz @f
		871	inc ecx
		872	cmp eax, ecx
		873	dec ecx
		874	jne @f
		875
		876	mov eax, ecx
		877	and [edx + TCP_segment.Flags], not TH_FIN
1529	hidnplayr	878	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1514	hidnplayr	879	jmp .no_duplicate
		880	@@:
		881
		882	; Handle the case when a bound socket connects to itself
		883	; Allow packets with a SYN and an ACKto continue with the processing
		884
		885	;-------------------------------------
		886	; Generate duplicate ACK if nescessary
		887
		888	; This code also handles simultaneous half-open or self-connects
		889
		890	test eax, eax
		891	jnz .drop_after_ack
		892
		893	cmp [edx + TCP_segment.Flags], TH_ACK
		894	jz .drop_after_ack
		895
		896	.duplicate:
		897
1529	hidnplayr	898	DEBUGF 1,"Duplicate received"
		899
1514	hidnplayr	900	;----------------------------------------
		901	; Update statistics for duplicate packets
		902
		903	;;; TODO
		904
1529	hidnplayr	905	jmp .drop ;;; DROP the packet ??
1514	hidnplayr	906
		907	.no_duplicate:
		908
		909	;-----------------------------------------------
		910	; Remove duplicate data and update urgent offset
		911
		912	add [edx + TCP_segment.SequenceNumber], eax
		913
		914	;;; TODO
		915
		916	sub [edx + TCP_segment.UrgentPointer], ax
		917	jg @f
		918
		919	and [edx + TCP_segment.Flags], not (TH_URG)
		920	mov [edx + TCP_segment.UrgentPointer], 0
		921	@@:
		922
		923	;--------------------------------------------------
		924	; Handle data that arrives after process terminates
		925
		926	cmp [ebx + SOCKET.PID], 0
		927	jge @f
		928
		929	cmp [ebx + TCP_SOCKET.t_state], TCB_CLOSE_WAIT
		930	jle @f
		931
		932	test ecx, ecx
		933	jz @f
		934
		935	;;; Close the socket
		936	;;; update stats
		937
		938	jmp .drop_with_reset
		939
		940	@@:
		941
		942	;----------------------------------------
		943	; Remove data beyond right edge of window
		944
		945	mov eax, [edx + TCP_segment.SequenceNumber]
		946	add eax, ecx
		947	sub eax, [ebx + TCP_SOCKET.RCV_NXT]
		948	sub ax, [ebx + TCP_SOCKET.RCV_WND]
		949
		950	; eax now holds the number of bytes to drop
		951
		952	jle .no_excess_data
		953
		954	;;; TODO: update stats
		955
		956	cmp eax, ecx
		957	jl .dont_drop_all
		958
		959	;;; TODO 700-736
		960
		961	.dont_drop_all:
		962
		963	.no_excess_data:
		964
		965	;-----------------
		966	; Record timestamp
		967
		968	;;; TODO 737-746
		969
		970	;------------------
		971	; Process RST flags
		972
		973	test [edx + TCP_segment.Flags], TH_RST
		974	jz .rst_skip
		975
1529	hidnplayr	976	DEBUGF 1,"Got an RST flag"
		977
1514	hidnplayr	978	mov eax, [ebx + TCP_SOCKET.t_state]
		979	shl eax, 2
		980	jmp dword [eax + .rst_sw_list]
		981
		982	.rst_sw_list:
		983	dd .rst_skip ;TCB_CLOSED
		984	dd .rst_skip ;TCB_LISTEN
		985	dd .rst_skip ;TCB_SYN_SENT
		986	dd .econnrefused ;TCB_SYN_RECEIVED
		987	dd .econnreset ;TCB_ESTABLISHED
		988	dd .econnreset ;TCB_CLOSE_WAIT
		989	dd .econnreset ;TCB_FIN_WAIT_1
		990	dd .rst_close ;TCB_CLOSING
		991	dd .rst_close ;TCB_LAST_ACK
		992	dd .econnreset ;TCB_FIN_WAIT_2
		993	dd .rst_close ;TCB_TIMED_WAIT
		994
		995	.econnrefused:
		996
1529	hidnplayr	997	DEBUGF 1,"Connection refused"
		998
1514	hidnplayr	999	;;; TODO: debug info
		1000
		1001	jmp .close
		1002
		1003	.econnreset:
		1004
1529	hidnplayr	1005	DEBUGF 1,"Connection reset"
		1006
1514	hidnplayr	1007	;;; TODO: debug info
1529	hidnplayr	1008	.close:
1514	hidnplayr	1009
1529	hidnplayr	1010	DEBUGF 1,"Closing connection"
		1011
1514	hidnplayr	1012	;;; update stats
		1013
		1014	.rst_close:
		1015
1529	hidnplayr	1016	DEBUGF 1,"Closing with reset"
		1017
1514	hidnplayr	1018	;;; Close the socket
		1019	jmp .drop
		1020
		1021	.rst_skip:
		1022
		1023	;--------------------------------------
		1024	; handle SYN-full and ACK-less segments
		1025
		1026	test [edx + TCP_segment.Flags], TH_SYN
		1027	jz @f
		1028
		1029	;;; tcp_drop ( ECONNRESET)
		1030	jmp .drop_with_reset
		1031
		1032	test [edx + TCP_segment.Flags], TH_ACK
		1033	jz .drop
		1034
		1035	;----------------
		1036	; Process the ACK
		1037
		1038	cmp [ebx + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		1039	jg .ack_dup
		1040	jl .ack_nodup
		1041
		1042	;;;;;
		1043
		1044	.ack_dup:
		1045
		1046	;;;;
		1047
		1048	.ack_nodup:
		1049
		1050	;;;; 887
		1051
		1052	;-------------------------------------------------
1519	hidnplayr	1053	; If the congestion window was inflated to account
1514	hidnplayr	1054	; for the other side's cached packets, retrace it
		1055
		1056	;;;; 888 - 902
		1057
		1058
		1059	;------------------------------------------
		1060	; RTT measurements and retransmission timer
		1061
		1062	;;;;; 903 - 926
		1063
1519	hidnplayr	1064	mov [ebx + TCP_SOCKET.timer_retransmission], 0
1514	hidnplayr	1065
1519	hidnplayr	1066	mov eax, [ebx + TCP_SOCKET.SND_MAX]
		1067	cmp eax, [edx + TCP_segment.AckNumber]
		1068	je .all_outstanding
		1069	mov [ebx + TCP_SOCKET.timer_retransmission], 120 ;;;; TODO: correct this value
		1070	.all_outstanding:
		1071
		1072
1514	hidnplayr	1073	;-------------------------------------------
		1074	; Open congestion window in response to ACKs
		1075
		1076	;;;;
		1077
		1078
		1079	;------------------------------------------
		1080	; Remove acknowledged data from send buffer
		1081
1529	hidnplayr	1082	lea eax, [ebx + snd]
		1083	mov ecx, ecx ;;;; 943 - 956
		1084	call SOCKET_ring_free
1514	hidnplayr	1085
		1086	;---------------------------------------
		1087	; Wake up process waiting on send buffer
		1088
1529	hidnplayr	1089	mov eax, ebx
		1090	call SOCKET_notify_owner
1514	hidnplayr	1091
		1092	mov eax, [ebx + TCP_SOCKET.t_state]
		1093	shl eax, 2
		1094	jmp dword [eax + .ACK_sw_list]
		1095
		1096	.ACK_sw_list:
		1097	dd .step6 ;TCB_CLOSED
		1098	dd .step6 ;TCB_LISTEN
		1099	dd .step6 ;TCB_SYN_SENT
		1100	dd .step6 ;TCB_SYN_RECEIVED
		1101	dd .step6 ;TCB_ESTABLISHED
		1102	dd .step6 ;TCB_CLOSE_WAIT
		1103	dd ._963 ;TCB_FIN_WAIT_1
		1104	dd ._958 ;TCB_CLOSING
		1105	dd ._999 ;TCB_LAST_ACK
		1106	dd .step6 ;TCB_FIN_WAIT_2
		1107	dd ._1010 ;TCB_TIMED_WAIT
		1108
		1109
		1110	._963:
		1111
		1112
		1113	jmp .step6
		1114
		1115
		1116	._958:
		1117
		1118	jmp .step6
		1119
		1120	._999:
		1121
		1122	jmp .step6
		1123
		1124
		1125	._1010:
		1126
		1127	jmp .step6
		1128
		1129
		1130
		1131	align 4
		1132	.step6:
		1133
		1134	DEBUGF 1,"step 6\n"
		1135
		1136	;--------------------------
		1137	; update window information
		1138
		1139	test [edx + TCP_segment.Flags], TH_ACK
		1140	jz .no_window_update
		1141
		1142	mov eax, [ebx + TCP_SOCKET.SND_WL1]
		1143	cmp eax, [edx + TCP_segment.SequenceNumber]
		1144
		1145	;;;; 1021
		1146
		1147	;----------------------------------
		1148	; Keep track of pure window updates
		1149
		1150	test ecx, ecx
		1151	jz @f
		1152
		1153	mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1154	cmp eax, [edx + TCP_segment.AckNumber]
		1155	jne @f
		1156
		1157	;; mov eax, tiwin
		1158	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		1159	jle @f
		1160
		1161	;;; update stats
		1162
		1163	@@:
		1164
		1165	;; mov eax, incoming window
		1166	cmp eax, [ebx + TCP_SOCKET.max_sndwnd]
		1167	jle @f
		1168	mov [ebx + TCP_SOCKET.max_sndwnd], eax
		1169	@@:
		1170	mov [ebx + TCP_SOCKET.SND_WND], eax
		1171
		1172	mov eax, [edx + TCP_segment.SequenceNumber]
		1173	mov [ebx + TCP_SOCKET.SND_WL1], eax
		1174
		1175	mov eax, [edx + TCP_segment.AckNumber]
		1176	mov [ebx + TCP_SOCKET.SND_WL2], eax
		1177
		1178	;;; needoutput = 1
		1179
		1180	.no_window_update:
		1181
		1182	;-----------------
		1183	; process URG flag
		1184
		1185	test [edx + TCP_segment.Flags], TH_URG
		1186	jz .not_urgent
		1187
		1188	cmp [edx + TCP_segment.UrgentPointer], 0
		1189	jz .not_urgent
		1190
		1191	cmp [ebx + TCP_SOCKET.t_state], TCB_TIMED_WAIT
		1192	je .not_urgent
		1193
		1194	; Ignore bogus urgent offsets
		1195
		1196	;;; 1040-1050
		1197
		1198	movzx eax, [edx + TCP_segment.UrgentPointer]
1529	hidnplayr	1199	add eax, [ebx + rcv.size]
1514	hidnplayr	1200	cmp eax, SOCKET_MAXDATA
		1201	jle .not_urgent
		1202
		1203	mov [edx + TCP_segment.UrgentPointer], 0
		1204	and [edx + TCP_segment.Flags], not (TH_URG)
		1205	jmp .do_data
		1206
		1207	.not_urgent:
		1208
		1209	;--------------------------------------
		1210	; processing of received urgent pointer
		1211
1529	hidnplayr	1212	;;; TODO (1051-1093)
1514	hidnplayr	1213
1529	hidnplayr	1214	;--------------------------------
		1215	; process the data in the segment
1514	hidnplayr	1216
1529	hidnplayr	1217	.do_data:
1514	hidnplayr	1218
1529	hidnplayr	1219	DEBUGF 1,"TCP: do data:\n"
1514	hidnplayr	1220
		1221	test [edx + TCP_segment.Flags], TH_FIN
1529	hidnplayr	1222	jnz .process_fin
1514	hidnplayr	1223
1529	hidnplayr	1224	test [ebx + TCP_SOCKET.t_state], TCB_FIN_WAIT_1
1514	hidnplayr	1225	jge .dont_do_data
		1226
		1227	DEBUGF 1,"Processing data in segment\n"
		1228
		1229	;;; NOW, process the data
		1230
		1231	jmp .final_processing
		1232
		1233
		1234	.dont_do_data:
		1235
		1236	;---------------
		1237	; FIN processing
		1238
		1239	.process_fin:
		1240
		1241	DEBUGF 1,"Processing FIN\n"
		1242
		1243	mov eax, [ebx + TCP_SOCKET.t_state]
		1244	shl eax, 2
		1245	jmp dword [eax + .FIN_sw_list]
		1246
		1247	.FIN_sw_list:
		1248	dd .no_fin ;TCB_CLOSED
		1249	dd .no_fin ;TCB_LISTEN
		1250	dd .no_fin ;TCB_SYN_SENT
		1251	dd ._1131 ;TCB_SYN_RECEIVED
		1252	dd ._1131 ;TCB_ESTABLISHED
		1253	dd .no_fin ;TCB_CLOSE_WAIT
		1254	dd ._1139 ;TCB_FIN_WAIT_1
		1255	dd .no_fin ;TCB_CLOSING
		1256	dd .no_fin ;TCB_LAST_ACK
		1257	dd ._1147 ;TCB_FIN_WAIT_2
		1258	dd ._1156 ;TCB_TIMED_WAIT
		1259
		1260
		1261
		1262	._1131:
		1263
		1264	._1139:
		1265
		1266	._1147:
		1267
		1268	._1156:
		1269
		1270
		1271	.no_fin:
		1272
		1273	;-----------------
		1274	; Final processing
		1275
		1276	.final_processing:
		1277
		1278	DEBUGF 1,"Final processing\n"
		1279
		1280	;;; if debug enabled, output packet
		1281
		1282	;test ;;;needoutput = 1
		1283	;jnz .outputnow
		1284
		1285	test [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1529	hidnplayr	1286	jnz .ack_now
1514	hidnplayr	1287
1529	hidnplayr	1288	mov [ebx + SOCKET.lock], 0
		1289	call kernel_free
		1290	add esp, 4
		1291	ret
		1292
		1293	.ack_now:
		1294
		1295	DEBUGF 1,"ACK now!\n"
		1296
		1297	push ebx
		1298	mov eax, ebx
1514	hidnplayr	1299	call TCP_output
1529	hidnplayr	1300	pop ebx
1514	hidnplayr	1301
		1302	mov [ebx + SOCKET.lock], 0
1274	hidnplayr	1303	call kernel_free
1529	hidnplayr	1304	add esp, 4
		1305	ret
1274	hidnplayr	1306
1514	hidnplayr	1307	;------------------------------------------
		1308	; Generate an ACK, droping incoming segment
1274	hidnplayr	1309
1514	hidnplayr	1310	align 4
		1311	.drop_after_ack:
1274	hidnplayr	1312
1514	hidnplayr	1313	DEBUGF 1,"Drop after ACK\n"
1274	hidnplayr	1314
1514	hidnplayr	1315	test [edx + TCP_segment.Flags], TH_RST
		1316	jnz .drop
1274	hidnplayr	1317
1514	hidnplayr	1318	and [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1274	hidnplayr	1319
1529	hidnplayr	1320	push ebx
		1321	mov eax, ebx
1514	hidnplayr	1322	call TCP_output
1529	hidnplayr	1323	pop ebx
1318	hidnplayr	1324
1514	hidnplayr	1325	mov [ebx + SOCKET.lock], 0
		1326	call kernel_free
1529	hidnplayr	1327	add esp, 4
		1328	ret
1274	hidnplayr	1329
1514	hidnplayr	1330
		1331	;-------------------------------------------
		1332	; Generate an RST, dropping incoming segment
		1333
		1334	align 4
		1335	.drop_with_reset:
		1336
		1337	DEBUGF 1,"Drop with reset\n"
		1338
		1339	test [edx + TCP_segment.Flags], TH_RST
		1340	jnz .drop
		1341
		1342	;;; if its a multicast/broadcast, also drop
		1343
		1344	test [edx + TCP_segment.Flags], TH_ACK
		1345	jnz .respond_ack
		1346
		1347	test [edx + TCP_segment.Flags], TH_SYN
		1348	jnz .respond_syn
		1349
		1350	mov [ebx + SOCKET.lock], 0
		1351	call kernel_free
1529	hidnplayr	1352	add esp, 4
		1353	ret
1514	hidnplayr	1354
		1355	.respond_ack:
		1356
		1357	;;;;
		1358
1529	hidnplayr	1359	call TCP_respond_segment
1514	hidnplayr	1360
		1361	jmp .destroy_new_socket
		1362
		1363
		1364	.respond_syn:
		1365
		1366	;;;;
		1367
1529	hidnplayr	1368	call TCP_respond_segment
1514	hidnplayr	1369
		1370	jmp .destroy_new_socket
		1371
		1372	;-----
		1373	; Drop
		1374
		1375	align 4
		1376	.drop:
		1377
		1378	DEBUGF 1,"Dropping packet\n"
		1379
		1380	;;;; If debugging options are enabled, output the packet somwhere
		1381
		1382	.destroy_new_socket:
		1383
		1384	;;;; kill the newly created socket
		1385
		1386	mov [ebx + SOCKET.lock], 0
		1387	call kernel_free
1529	hidnplayr	1388	add esp, 4
		1389	ret
1514	hidnplayr	1390
		1391
		1392
		1393
		1394
		1395
		1396	;---------------------------
		1397	;
		1398	; TCP_pull_out_of_band
		1399	;
		1400	; IN: eax =
		1401	; ebx = socket ptr
		1402	; edx = tcp packet ptr
		1403	;
		1404	; OUT: /
		1405	;
		1406	;---------------------------
		1407
		1408	align 4
		1409	TCP_pull_out_of_band:
		1410
		1411	DEBUGF 1,"TCP_pull_out_of_band\n"
		1412
		1413	;;;; 1282-1305
		1414
1318	hidnplayr	1415	ret
		1416
		1417
		1418
		1419	;-----------------------------------------------------------------
		1420	;
1514	hidnplayr	1421	; TCP_output
1318	hidnplayr	1422	;
1519	hidnplayr	1423	; IN: eax = socket pointer
1514	hidnplayr	1424	;; esi = ptr to data
		1425	;; ecx = number of data bytes
		1426	;
1318	hidnplayr	1427	; OUT: /
		1428	;
		1429	;-----------------------------------------------------------------
		1430	align 4
1514	hidnplayr	1431	TCP_output:
1318	hidnplayr	1432
1514	hidnplayr	1433	DEBUGF 1,"TCP_output, socket: %x\n", eax
1318	hidnplayr	1434
1514	hidnplayr	1435	; We'll detect the length of the data to be transmitted, and flags to be used
		1436	; If there is some data, or any critical controls to send (SYN / RST), then transmit
		1437	; Otherwise, investigate further
1318	hidnplayr	1438
1514	hidnplayr	1439	mov ebx, [eax + TCP_SOCKET.SND_MAX]
		1440	cmp ebx, [eax + TCP_SOCKET.SND_UNA]
		1441	jne .not_idle
1318	hidnplayr	1442
1514	hidnplayr	1443	mov ebx, [eax + TCP_SOCKET.t_idle]
		1444	cmp ebx, [eax + TCP_SOCKET.t_rxtcur]
		1445	jle .not_idle
1318	hidnplayr	1446
1514	hidnplayr	1447	; We have been idle for a while and no ACKS are expected to clock out any data we send..
		1448	; Slow start to get ack "clock" running again.
1318	hidnplayr	1449
1514	hidnplayr	1450	mov ebx, [eax + TCP_SOCKET.t_maxseg]
		1451	mov [eax + TCP_SOCKET.SND_CWND], ebx
1318	hidnplayr	1452
1514	hidnplayr	1453	.not_idle:
		1454	.again:
		1455	mov ebx, [eax + TCP_SOCKET.SND_NXT] ; calculate offset
		1456	sub ebx, [eax + TCP_SOCKET.SND_UNA] ;
1318	hidnplayr	1457
1514	hidnplayr	1458	mov ecx, [eax + TCP_SOCKET.SND_WND] ; determine window
		1459	cmp ecx, [eax + TCP_SOCKET.SND_CWND] ;
		1460	jl @f ;
		1461	mov ecx, [eax + TCP_SOCKET.SND_CWND] ;
		1462	@@: ;
1318	hidnplayr	1463
1529	hidnplayr	1464	call TCP_outflags ; in dl
1318	hidnplayr	1465
1514	hidnplayr	1466	; If in persist timeout with window of 0, send 1 byte.
		1467	; Otherwise, if window is small but nonzero, and timer expired,
		1468	; we will send what we can and go to transmit state
1318	hidnplayr	1469
1514	hidnplayr	1470	test [eax + TCP_SOCKET.t_force], -1
		1471	jz .no_persist_timeout
1318	hidnplayr	1472
1514	hidnplayr	1473	test ecx, ecx
		1474	jnz .no_zero_window
1255	hidnplayr	1475
1529	hidnplayr	1476	cmp ebx, [eax + snd.size]
1514	hidnplayr	1477	jge @f
1255	hidnplayr	1478
1514	hidnplayr	1479	and dl, not (TH_FIN) ; clear the FIN flag ??? how can it be set before?
1255	hidnplayr	1480
1514	hidnplayr	1481	@@:
		1482	inc ecx
		1483	jmp .no_persist_timeout
1255	hidnplayr	1484
1514	hidnplayr	1485	.no_zero_window:
1254	hidnplayr	1486
1529	hidnplayr	1487	mov [eax + TCP_SOCKET.timer_persist], 0 ;;;;
1514	hidnplayr	1488	mov [eax + TCP_SOCKET.t_rxtshift], 0
1254	hidnplayr	1489
1514	hidnplayr	1490	.no_persist_timeout:
1159	hidnplayr	1491
1514	hidnplayr	1492	;;;106
1159	hidnplayr	1493
1529	hidnplayr	1494	mov esi, [eax + snd.size]
1514	hidnplayr	1495	cmp esi, ecx
		1496	jl @f
		1497	mov esi, ecx
		1498	@@:
		1499	sub esi, ebx
1254	hidnplayr	1500
1514	hidnplayr	1501	cmp esi, -1
		1502	jne .not_minus_one
1159	hidnplayr	1503
1514	hidnplayr	1504	; If FIN has been set, but not ACKed, and we havent been called to retransmit,
		1505	; len (esi) will be -1
		1506	; Otherwise, window shrank after we sent into it.
		1507	; If window shrank to 0, cancel pending retransmit and pull SND_NXT back to (closed) window
		1508	; We will enter persist state below.
		1509	; If window didn't close completely, just wait for an ACK
1159	hidnplayr	1510
1514	hidnplayr	1511	xor esi, esi
1159	hidnplayr	1512
1514	hidnplayr	1513	test ecx, ecx
		1514	jnz @f
1159	hidnplayr	1515
1529	hidnplayr	1516	mov [eax + TCP_SOCKET.timer_retransmission], 0 ; cancel retransmit
1274	hidnplayr	1517
1514	hidnplayr	1518	push [eax + TCP_SOCKET.SND_UNA]
		1519	pop [eax + TCP_SOCKET.SND_NXT]
		1520	@@:
1254	hidnplayr	1521
1514	hidnplayr	1522	.not_minus_one:
1254	hidnplayr	1523
1514	hidnplayr	1524	;;; 124
1159	hidnplayr	1525
1514	hidnplayr	1526	cmp esi, [eax + TCP_SOCKET.t_maxseg]
		1527	jle @f
1274	hidnplayr	1528
1514	hidnplayr	1529	mov esi, [eax + TCP_SOCKET.t_maxseg]
		1530	;sendalot = 1
1274	hidnplayr	1531
1514	hidnplayr	1532	@@:
1274	hidnplayr	1533
1514	hidnplayr	1534	;;; 128
1274	hidnplayr	1535
1514	hidnplayr	1536	mov edi, [eax + TCP_SOCKET.SND_NXT]
		1537	add edi, esi ; len
		1538	sub edi, [eax + TCP_SOCKET.SND_UNA]
1529	hidnplayr	1539	add edi, [eax + snd.size]
1514	hidnplayr	1540	cmp edi, 0
		1541	jle @f
1274	hidnplayr	1542
1514	hidnplayr	1543	and dl, not (TH_FIN) ; clear the FIN flag
1159	hidnplayr	1544
1514	hidnplayr	1545	@@:
1159	hidnplayr	1546
		1547
1529	hidnplayr	1548	; set ecx to space available in receive buffer
		1549	; From now on, ecx will be the window we advertise to the other end
1159	hidnplayr	1550
1529	hidnplayr	1551	mov ecx, SOCKET_MAXDATA
		1552	sub ecx, [eax + rcv.size]
1159	hidnplayr	1553
1514	hidnplayr	1554	;------------------------------
		1555	; Sender silly window avoidance
1159	hidnplayr	1556
1529	hidnplayr	1557	cmp ecx, [eax + TCP_SOCKET.t_maxseg]
1514	hidnplayr	1558	je .send
1274	hidnplayr	1559
1514	hidnplayr	1560	;;; TODO: 144-145
1274	hidnplayr	1561
1514	hidnplayr	1562	test [eax + TCP_SOCKET.t_force], -1
		1563	jnz .send
1274	hidnplayr	1564
1529	hidnplayr	1565	mov ebx, [eax + TCP_SOCKET.max_sndwnd]
		1566	shr ebx, 1
		1567	cmp ecx, ebx
		1568	jge .send
1274	hidnplayr	1569
1529	hidnplayr	1570	mov ebx, [eax + TCP_SOCKET.SND_NXT]
		1571	cmp ebx, [eax + TCP_SOCKET.SND_MAX]
		1572	jl .send
1254	hidnplayr	1573
1514	hidnplayr	1574	;----------------------------------------
		1575	; Check if a window update should be sent
1159	hidnplayr	1576
1529	hidnplayr	1577	test ecx, ecx ; window
		1578	jz .no_window
1159	hidnplayr	1579
1514	hidnplayr	1580	;;; TODO 154-172
1159	hidnplayr	1581
1514	hidnplayr	1582	.no_window:
1159	hidnplayr	1583
1514	hidnplayr	1584	;--------------------------
		1585	; Should a segment be sent?
1159	hidnplayr	1586
1514	hidnplayr	1587	test [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
		1588	jnz .send
1159	hidnplayr	1589
1514	hidnplayr	1590	test dl, TH_SYN + TH_RST
		1591	jnz .send
1159	hidnplayr	1592
1514	hidnplayr	1593	mov eax, [ebx + TCP_SOCKET.SND_UP]
		1594	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
		1595	jg .send
1249	hidnplayr	1596
1514	hidnplayr	1597	test dl, TH_FIN
		1598	jz .enter_persist
1318	hidnplayr	1599
1514	hidnplayr	1600	test [ebx + TCP_SOCKET.t_flags], TF_SENTFIN
		1601	jnz .send
1254	hidnplayr	1602
1514	hidnplayr	1603	mov eax, [ebx + TCP_SOCKET.SND_NXT]
		1604	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
		1605	je .send
1254	hidnplayr	1606
1514	hidnplayr	1607	;--------------------
		1608	; Enter persist state
1318	hidnplayr	1609
1514	hidnplayr	1610	.enter_persist:
1318	hidnplayr	1611
1519	hidnplayr	1612	DEBUGF 1,"Entering persist state\n"
1318	hidnplayr	1613
1514	hidnplayr	1614	;--------------------------------------
		1615	; No reason to send a segment, just ret
1318	hidnplayr	1616
1514	hidnplayr	1617	DEBUGF 1,"No reason to send a segment\n"
1318	hidnplayr	1618
1514	hidnplayr	1619	ret
1318	hidnplayr	1620
		1621
1514	hidnplayr	1622	;-----------------------------------------------
		1623	;
		1624	; Send a segment
		1625	;
1529	hidnplayr	1626	; eax = socket pointer
1514	hidnplayr	1627	; dl = flags
		1628	;
		1629	;-----------------------------------------------
1318	hidnplayr	1630
1529	hidnplayr	1631	.send:
1318	hidnplayr	1632
1514	hidnplayr	1633	DEBUGF 1,"Preparing to send a segment\n"
1318	hidnplayr	1634
1529	hidnplayr	1635	mov edi, TCP_segment.Data ; edi will contain headersize
1318	hidnplayr	1636
1529	hidnplayr	1637	sub esp, 8 ; create some space on stack
		1638	push eax ; save this too..
		1639
1514	hidnplayr	1640	;------------------------------------
		1641	; Send options with first SYN segment
1318	hidnplayr	1642
1514	hidnplayr	1643	test dl, TH_SYN
		1644	jz .no_options
1318	hidnplayr	1645
1529	hidnplayr	1646	push [eax + TCP_SOCKET.ISS]
		1647	pop [eax + TCP_SOCKET.SND_NXT]
1318	hidnplayr	1648
1529	hidnplayr	1649	test [eax + TCP_SOCKET.t_flags], TF_NOOPT
1514	hidnplayr	1650	jnz .no_options
1318	hidnplayr	1651
1529	hidnplayr	1652	mov ecx, 1460
		1653	or ecx, TCP_OPT_MAXSEG shl 24 + 4 shl 16
		1654	bswap ecx
		1655	push ecx
		1656	add di, 4
1514	hidnplayr	1657
1529	hidnplayr	1658	test [eax + TCP_SOCKET.t_flags], TF_REQ_SCALE
1514	hidnplayr	1659	jz .no_syn
		1660
		1661	test dl, TH_ACK
		1662	jnz .scale_opt
		1663
1529	hidnplayr	1664	test [eax + TCP_SOCKET.t_flags], TF_RCVD_SCALE
1514	hidnplayr	1665	jz .no_syn
		1666
		1667	.scale_opt:
1529	hidnplayr	1668	movzx ecx, byte [eax + TCP_SOCKET.request_r_scale]
		1669	or ecx, TCP_OPT_WINDOW shl 24 + 4 shl 16 + TCP_OPT_NOP shl 8
		1670	bswap ecx
		1671	pushd ecx
1514	hidnplayr	1672	add di, 4
1159	hidnplayr	1673
1514	hidnplayr	1674	.no_syn:
1159	hidnplayr	1675
1514	hidnplayr	1676	;------------------------------------
		1677	; Make the timestamp option if needed
1159	hidnplayr	1678
1529	hidnplayr	1679	test [eax + TCP_SOCKET.t_flags], TF_REQ_TSTMP
1514	hidnplayr	1680	jz .no_timestamp
1159	hidnplayr	1681
1514	hidnplayr	1682	test dl, TH_RST
		1683	jnz .no_timestamp
		1684
		1685	test dl, TH_ACK
		1686	jz .timestamp
		1687
1529	hidnplayr	1688	test [eax + TCP_SOCKET.t_flags], TF_RCVD_TSTMP
1514	hidnplayr	1689	jz .no_timestamp
		1690
		1691	.timestamp:
1529	hidnplayr	1692	mov esi, [timer_ticks]
		1693	bswap esi
		1694	push esi
1514	hidnplayr	1695	pushw 0
1529	hidnplayr	1696	pushd TCP_OPT_TIMESTAMP + 10 shl 8 + TCP_OPT_NOP shl 16 + TCP_OPT_NOP shl 24
1514	hidnplayr	1697	add di, 10
		1698
		1699	.no_timestamp:
		1700	;; TODO: check if we dont exceed the max segment size
		1701
		1702	.no_options:
1529	hidnplayr	1703	; eax = socket ptr
		1704	; edx = flags
		1705	; ecx = data size
		1706	; edi = header size
		1707	; esi = snd ring buff ptr
1514	hidnplayr	1708
1529	hidnplayr	1709	xor ecx, ecx ;;;;;
1514	hidnplayr	1710	add ecx, edi ; total TCP segment size
		1711
1529	hidnplayr	1712	; Start by pushing all TCP header values in reverse order on stack
		1713	; (essentially, creating the tcp header!)
1514	hidnplayr	1714
1529	hidnplayr	1715	pushw 0 ; .UrgentPointer dw ?
		1716	pushw 0 ; .Checksum dw ?
		1717	pushw 0x00a0 ; .Window dw ? ;;;;;;;
		1718	shl edi, 2 ; .DataOffset db ? only 4 left-most bits
		1719	shl dx, 8
		1720	or dx, di ; .Flags db ?
		1721	pushw dx
		1722	shr edi, 2 ; .DataOffset db ? ;;;;
1514	hidnplayr	1723
1529	hidnplayr	1724	push [eax + TCP_SOCKET.RCV_NXT] ; .AckNumber dd ?
		1725	ntohld [esp]
1159	hidnplayr	1726
1529	hidnplayr	1727	push [eax + TCP_SOCKET.SND_NXT] ; .SequenceNumber dd ?
		1728	ntohld [esp]
1159	hidnplayr	1729
1529	hidnplayr	1730	push [eax + TCP_SOCKET.RemotePort] ; .DestinationPort dw ?
		1731	ntohlw [esp]
1249	hidnplayr	1732
1529	hidnplayr	1733	push [eax + TCP_SOCKET.LocalPort] ; .SourcePort dw ?
		1734	ntohlw [esp]
1274	hidnplayr	1735
1529	hidnplayr	1736	push edi ; header size
1274	hidnplayr	1737
1529	hidnplayr	1738	; Create the IP packet
		1739	mov ebx, [eax + IP_SOCKET.LocalIP] ; source ip
		1740	mov eax, [eax + IP_SOCKET.RemoteIP] ; dest ip
		1741	; mov ecx, ; data length
		1742	; mov dx, ; fragment id
		1743	mov di, IP_PROTO_TCP shl 8 + 128
		1744	call IPv4_output
		1745	jz .fail
1274	hidnplayr	1746
1529	hidnplayr	1747	;-----------------------------------------
		1748	; Move TCP header from stack to TCP packet
1274	hidnplayr	1749
1529	hidnplayr	1750	; pop ecx ; header size
		1751	; mov esi, esp
		1752	; add esp, ecx
		1753	; shr ecx, 2
		1754	; rep movsd
1274	hidnplayr	1755
1529	hidnplayr	1756	mov ecx, [esp]
		1757	lea esi, [esp+4]
		1758	shr ecx, 2
		1759	rep movsd
1274	hidnplayr	1760
1529	hidnplayr	1761	pop ecx
		1762	add esp, ecx
1254	hidnplayr	1763
1530	hidnplayr	1764	mov [esp + 4+4], edx ; packet size
		1765	mov [esp + 4], eax ; packet ptr
1254	hidnplayr	1766
1529	hidnplayr	1767	mov edx, edi
		1768	sub edx, ecx
1159	hidnplayr	1769
1514	hidnplayr	1770	;--------------
		1771	; Copy the data
1159	hidnplayr	1772
1529	hidnplayr	1773	; eax = ptr to ring struct
		1774	; ecx = buffer size
		1775	; edi = ptr to buffer
1249	hidnplayr	1776
1529	hidnplayr	1777	mov eax, [esp] ; socket ptr
		1778	push ecx edx
		1779	add eax, snd
		1780	call SOCKET_ring_read
		1781	pop esi ecx
		1782	pop eax
1254	hidnplayr	1783
1529	hidnplayr	1784	;-------------------------------------------------------------
		1785	; Create the checksum (we have already pushed IPs onto stack)
1254	hidnplayr	1786
1529	hidnplayr	1787	DEBUGF 1,"checksum: ptr=%x size=%u\n", esi, ecx
1159	hidnplayr	1788
1529	hidnplayr	1789	TCP_checksum (eax + IP_SOCKET.LocalIP), (eax + IP_SOCKET.RemoteIP)
		1790	mov [esi+TCP_segment.Checksum], dx
		1791
1514	hidnplayr	1792	;----------------
		1793	; Send the packet
1159	hidnplayr	1794
1529	hidnplayr	1795	DEBUGF 1,"Sending TCP Packet to device %x\n", ebx
		1796	call [ebx + NET_DEVICE.transmit]
		1797	ret
1159	hidnplayr	1798
1514	hidnplayr	1799
1529	hidnplayr	1800	.fail:
		1801	pop ecx
		1802	add esp, ecx
		1803	add esp, 4+4+8+4
		1804	DEBUGF 1,"TCP_output: failed\n"
1159	hidnplayr	1805	ret
		1806
1529	hidnplayr	1807
		1808
1514	hidnplayr	1809	;-------------------------
		1810	;
		1811	; TCP_outflags
		1812	;
		1813	; IN: eax = socket ptr
		1814	;
		1815	; OUT: edx = flags
		1816	;
		1817	;-------------------------
1249	hidnplayr	1818	align 4
1514	hidnplayr	1819	TCP_outflags:
1254	hidnplayr	1820
1514	hidnplayr	1821	mov edx, [eax + TCP_SOCKET.t_state]
		1822	movzx edx, byte [edx + .flaglist]
1254	hidnplayr	1823
1514	hidnplayr	1824	DEBUGF 1,"TCP_outflags, socket: %x, flags: %x\n", eax, dl
		1825
1159	hidnplayr	1826	ret
		1827
1514	hidnplayr	1828	.flaglist:
1159	hidnplayr	1829
1514	hidnplayr	1830	db TH_RST + TH_ACK ; TCB_CLOSED
		1831	db 0 ; TCB_LISTEN
		1832	db TH_SYN ; TCB_SYN_SENT
		1833	db TH_SYN + TH_ACK ; TCB_SYN_RECEIVED
		1834	db TH_ACK ; TCB_ESTABLISHED
		1835	db TH_ACK ; TCB_CLOSE_WAIT
		1836	db TH_SYN + TH_ACK ; TCB_FIN_WAIT_1
		1837	db TH_SYN + TH_ACK ; TCB_CLOSING
		1838	db TH_SYN + TH_ACK ; TCB_LAST_ACK
		1839	db TH_ACK ; TCB_FIN_WAIT_2
		1840	db TH_ACK ; TCB_TIMED_WAIT
1249	hidnplayr	1841
1514	hidnplayr	1842
1529	hidnplayr	1843
		1844
1514	hidnplayr	1845	;-------------------------
		1846	;
		1847	; TCP_drop
		1848	;
		1849	; IN: eax = socket ptr
		1850	;
		1851	; OUT: /
		1852	;
		1853	;-------------------------
1249	hidnplayr	1854	align 4
1514	hidnplayr	1855	TCP_drop:
1254	hidnplayr	1856
1514	hidnplayr	1857	DEBUGF 1,"TCP_drop\n"
1254	hidnplayr	1858
1514	hidnplayr	1859	; cmp [eax + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		1860	; jl .no_syn_received
1159	hidnplayr	1861
1514	hidnplayr	1862	mov [eax + TCP_SOCKET.t_state], TCB_CLOSED
1159	hidnplayr	1863
1514	hidnplayr	1864	call TCP_output
1254	hidnplayr	1865
1514	hidnplayr	1866	; .no_syn_received:
		1867
1159	hidnplayr	1868	ret
		1869
		1870
1254	hidnplayr	1871
		1872
1159	hidnplayr	1873
1514	hidnplayr	1874	;---------------------------------------
		1875	;
1519	hidnplayr	1876	; The easy way to send an ACK/RST/keepalive segment
1514	hidnplayr	1877	;
1529	hidnplayr	1878	; TCP_respond_socket:
		1879	;
		1880	; IN: ebx = socket ptr
1519	hidnplayr	1881	; cl = flags
1514	hidnplayr	1882	;
1529	hidnplayr	1883	;--------------------------------------
1514	hidnplayr	1884	align 4
1529	hidnplayr	1885	TCP_respond_socket:
1254	hidnplayr	1886
1529	hidnplayr	1887	DEBUGF 1,"TCP_respond_socket\n"
1159	hidnplayr	1888
1519	hidnplayr	1889	;---------------------
		1890	; Create the IP packet
		1891
1529	hidnplayr	1892	push cx ebx
		1893	mov eax, [ebx + IP_SOCKET.RemoteIP]
		1894	mov ebx, [ebx + IP_SOCKET.LocalIP]
1519	hidnplayr	1895	mov ecx, TCP_segment.Data
1529	hidnplayr	1896	mov di , IP_PROTO_TCP shl 8 + 128
		1897	call IPv4_output
1519	hidnplayr	1898	test edi, edi
		1899	jz .error
1529	hidnplayr	1900	pop esi cx
		1901	push edx eax
1519	hidnplayr	1902
1529	hidnplayr	1903	;-----------------------------------------------
		1904	; Fill in the TCP header by using the socket ptr
1519	hidnplayr	1905
1529	hidnplayr	1906	mov ax, [esi + TCP_SOCKET.LocalPort]
		1907	rol ax, 8
		1908	stosw
		1909	mov ax, [esi + TCP_SOCKET.RemotePort]
		1910	rol ax, 8
		1911	stosw
		1912	mov eax, [esi + TCP_SOCKET.SND_NXT]
		1913	bswap eax
		1914	stosd
		1915	mov eax, [esi + TCP_SOCKET.RCV_NXT]
		1916	bswap eax
		1917	stosd
		1918	mov al, 0x50 ; Dataoffset: 20 bytes
		1919	stosb
		1920	mov al, cl
		1921	stosb
		1922	mov ax, [esi + TCP_SOCKET.RCV_WND]
		1923	rol ax, 8
		1924	stosw ; window
		1925	xor eax, eax
		1926	stosd ; checksum + urgentpointer
1519	hidnplayr	1927
		1928	;---------------------
		1929	; Fill in the checksum
		1930
		1931	.checksum:
1529	hidnplayr	1932	sub edi, TCP_segment.Data
		1933	mov ecx, TCP_segment.Data
		1934	xchg esi, edi
		1935	TCP_checksum (edi + IP_SOCKET.LocalIP), (esi + IP_SOCKET.RemoteIP)
		1936	mov [esi+TCP_segment.Checksum], dx
1519	hidnplayr	1937
		1938	;--------------------
		1939	; And send the segment
		1940
		1941	call [ebx + NET_DEVICE.transmit]
1159	hidnplayr	1942	ret
		1943
1519	hidnplayr	1944	.error:
1529	hidnplayr	1945	DEBUGF 1,"TCP_respond failed\n"
		1946	add esp, 2+4
1159	hidnplayr	1947
1519	hidnplayr	1948	ret
1514	hidnplayr	1949
1529	hidnplayr	1950
		1951
		1952	;-------------------------
		1953	; TCP_respond.segment:
		1954	;
		1955	; IN: edx = segment ptr (a previously received segment)
		1956	; cl = flags
		1957
		1958	align 4
		1959	TCP_respond_segment:
		1960
		1961	DEBUGF 1,"TCP_respond_segment\n"
		1962
		1963	;---------------------
		1964	; Create the IP packet
		1965
		1966	push cx edx
		1967	mov ebx, [edx - 20 + IPv4_Packet.SourceAddress] ;;;; and what if ip packet had options?!
		1968	mov eax, [edx - 20 + IPv4_Packet.DestinationAddress] ;;;
		1969	mov ecx, TCP_segment.Data
		1970	mov di , IP_PROTO_TCP shl 8 + 128
		1971	call IPv4_output
		1972	test edi, edi
		1973	jz .error
		1974
		1975	pop esi cx
		1976	push edx eax
		1977
1519	hidnplayr	1978	;---------------------------------------------------
		1979	; Fill in the TCP header by using a received segment
		1980
		1981	mov ax, [esi + TCP_segment.DestinationPort]
		1982	rol ax, 8
		1983	stosw
		1984	mov ax, [esi + TCP_segment.SourcePort]
		1985	rol ax, 8
		1986	stosw
		1987	mov eax, [esi + TCP_segment.AckNumber]
		1988	bswap eax
		1989	stosd
		1990	xor eax, eax
		1991	stosd
		1992	mov al, 0x50 ; Dataoffset: 20 bytes
		1993	stosb
		1994	mov al, cl
		1995	stosb
		1996	mov ax, 1280
		1997	rol ax, 8
		1998	stosw ; window
		1999	xor eax, eax
		2000	stosd ; checksum + urgentpointer
		2001
1529	hidnplayr	2002	;---------------------
		2003	; Fill in the checksum
1519	hidnplayr	2004
1529	hidnplayr	2005	.checksum:
		2006	lea esi, [edi - TCP_segment.Data]
		2007	mov ecx, TCP_segment.Data
		2008	TCP_checksum (esi - 20 + IPv4_Packet.DestinationAddress), (esi - 20 + IPv4_Packet.DestinationAddress)
		2009	mov [esi+TCP_segment.Checksum], dx
1519	hidnplayr	2010
1529	hidnplayr	2011	;--------------------
		2012	; And send the segment
1519	hidnplayr	2013
1529	hidnplayr	2014	call [ebx + NET_DEVICE.transmit]
		2015	ret
1519	hidnplayr	2016
1529	hidnplayr	2017	.error:
		2018	DEBUGF 1,"TCP_respond failed\n"
		2019	add esp, 2+4
1519	hidnplayr	2020
		2021	ret
		2022
		2023
		2024
1254	hidnplayr	2025
		2026	;---------------------------------------------------------------------------
		2027	;
		2028	; TCP_API
		2029	;
		2030	; This function is called by system function 75
		2031	;
		2032	; IN: subfunction number in bl
		2033	; device number in bh
		2034	; ecx, edx, .. depends on subfunction
		2035	;
		2036	; OUT:
		2037	;
		2038	;---------------------------------------------------------------------------
		2039	align 4
		2040	TCP_API:
		2041
		2042	movzx eax, bh
		2043	shl eax, 2
		2044
		2045	test bl, bl
		2046	jz .packets_tx ; 0
		2047	dec bl
		2048	jz .packets_rx ; 1
		2049
		2050	.error:
		2051	mov eax, -1
		2052	ret
		2053
		2054	.packets_tx:
1514	hidnplayr	2055	add eax, TCP_segments_tx
1254	hidnplayr	2056	mov eax, [eax]
		2057	ret
		2058
		2059	.packets_rx:
1514	hidnplayr	2060	add eax, TCP_segments_rx
1254	hidnplayr	2061	mov eax, [eax]
		2062	ret

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(root)/kernel/branches/net/network/tcp.inc @ 1533 – Rev 1530