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: 1716 $
1159	hidnplayr	20
1514	hidnplayr	21	; Socket states
		22	TCB_CLOSED equ 0
		23	TCB_LISTEN equ 1
		24	TCB_SYN_SENT equ 2
		25	TCB_SYN_RECEIVED equ 3
		26	TCB_ESTABLISHED equ 4
		27	TCB_CLOSE_WAIT equ 5
		28	TCB_FIN_WAIT_1 equ 6
		29	TCB_CLOSING equ 7
		30	TCB_LAST_ACK equ 8
		31	TCB_FIN_WAIT_2 equ 9
		32	TCB_TIMED_WAIT equ 10
1196	hidnplayr	33
1514	hidnplayr	34	; Socket Flags
		35	TF_ACKNOW equ 1 shl 0 ; ack peer immediately
		36	TF_DELACK equ 1 shl 1 ; ack, but try to delay it
		37	TF_NODELAY equ 1 shl 2 ; don't delay packets to coalesce
		38	TF_NOOPT equ 1 shl 3 ; don't use tcp options
		39	TF_SENTFIN equ 1 shl 4 ; have sent FIN
		40	TF_REQ_SCALE equ 1 shl 5 ; have/will request window scaling
		41	TF_RCVD_SCALE equ 1 shl 6 ; other side has requested scaling
		42	TF_REQ_TSTMP equ 1 shl 7 ; have/will request timestamps
		43	TF_RCVD_TSTMP equ 1 shl 8 ; a timestamp was received in SYN
		44	TF_SACK_PERMIT equ 1 shl 9 ; other side said I could SACK
1249	hidnplayr	45
1514	hidnplayr	46	; Segment flags
		47	TH_FIN equ 1 shl 0
		48	TH_SYN equ 1 shl 1
		49	TH_RST equ 1 shl 2
		50	TH_PUSH equ 1 shl 3
		51	TH_ACK equ 1 shl 4
		52	TH_URG equ 1 shl 5
1318	hidnplayr	53
1514	hidnplayr	54	; Segment header options
		55	TCP_OPT_EOL equ 0 ; End of option list.
		56	TCP_OPT_NOP equ 1 ; No-Operation.
		57	TCP_OPT_MAXSEG equ 2 ; Maximum Segment Size.
		58	TCP_OPT_WINDOW equ 3 ; window scale
		59	TCP_OPT_TIMESTAMP equ 8
		60
1519	hidnplayr	61	; Fundamental timer values
		62	TCP_time_MSL equ 47 ; max segment lifetime (30s)
		63	TCP_time_re_min equ 2 ; min retransmission (1,28s)
		64	TCP_time_re_max equ 100 ; max retransmission (64s)
		65	TCP_time_pers_min equ 8 ; min persist (5,12s)
		66	TCP_time_pers_max equ 94 ; max persist (60,16s)
		67	TCP_time_keep_init equ 118 ; connectione stablishment (75,52s)
		68	TCP_time_keep_idle equ 4608 ; idle time before 1st probe (2h)
		69	TCP_time_keep_interval equ 118 ; between probes when no response (75,52s)
		70	TCP_time_rtt_default equ 5 ; default Round Trip Time (3,2s)
		71
		72	; timer constants
		73	TCP_max_rxtshift equ 12 ; max retransmissions waiting for ACK
		74	TCP_max_keepcnt equ 8 ; max keepalive probes
		75
1529	hidnplayr	76	;
		77	TCP_max_winshift equ 14
		78	TCP_max_win equ 65535
1519	hidnplayr	79
1514	hidnplayr	80	struct TCP_segment
1159	hidnplayr	81	.SourcePort dw ?
		82	.DestinationPort dw ?
		83	.SequenceNumber dd ?
		84	.AckNumber dd ?
1196	hidnplayr	85	.DataOffset db ? ; DataOffset[0-3 bits] and Reserved[4-7]
		86	.Flags db ? ; Reserved[0-1 bits]\|URG\|ACK\|PSH\|RST\|SYN\|FIN
1159	hidnplayr	87	.Window dw ?
		88	.Checksum dw ?
		89	.UrgentPointer dw ?
1514	hidnplayr	90	.Data: ; ..or options
1159	hidnplayr	91	ends
		92
1196	hidnplayr	93	align 4
		94	uglobal
1514	hidnplayr	95	TCP_segments_tx rd IP_MAX_INTERFACES
		96	TCP_segments_rx rd IP_MAX_INTERFACES
		97	TCP_bytes_rx rq IP_MAX_INTERFACES
		98	TCP_bytes_tx rq IP_MAX_INTERFACES
		99	TCP_sequence_num dd ?
1196	hidnplayr	100	endg
		101
		102
		103	;-----------------------------------------------------------------
		104	;
		105	; TCP_init
		106	;
		107	; This function resets all TCP variables
		108	;
		109	;-----------------------------------------------------------------
1529	hidnplayr	110	macro TCP_init {
1196	hidnplayr	111
		112	xor eax, eax
1514	hidnplayr	113	mov edi, TCP_segments_tx
		114	mov ecx, (6*IP_MAX_INTERFACES)
1196	hidnplayr	115	rep stosd
		116
1529	hidnplayr	117	pseudo_random eax
		118	mov [TCP_sequence_num], eax
1196	hidnplayr	119
1529	hidnplayr	120	}
1196	hidnplayr	121
		122
1519	hidnplayr	123	;----------------------
1196	hidnplayr	124	;
1159	hidnplayr	125	;
1519	hidnplayr	126	;----------------------
1529	hidnplayr	127	macro TCP_timer_160ms {
1159	hidnplayr	128
1529	hidnplayr	129	local .loop
		130	local .exit
		131
1514	hidnplayr	132	mov eax, net_sockets
		133	.loop:
		134	mov eax, [eax + SOCKET.NextPtr]
		135	or eax, eax
1159	hidnplayr	136	jz .exit
		137
1542	hidnplayr	138	cmp [eax + SOCKET.Protocol], IP_PROTO_TCP ;;; We should also check if family is AF_INET
1514	hidnplayr	139	jne .loop
1249	hidnplayr	140
1519	hidnplayr	141	dec [eax + TCP_SOCKET.timer_ack]
1514	hidnplayr	142	jnz .loop
1159	hidnplayr	143
1519	hidnplayr	144	DEBUGF 1,"TCP ack for socket %x expired, time to piggyback!\n", eax
1159	hidnplayr	145
1519	hidnplayr	146	push eax
1529	hidnplayr	147	call TCP_respond_socket
1514	hidnplayr	148	pop eax
1159	hidnplayr	149
1519	hidnplayr	150	jmp .loop
1159	hidnplayr	151
		152	.exit:
1519	hidnplayr	153
1529	hidnplayr	154	}
1159	hidnplayr	155
		156
1519	hidnplayr	157	;-----------------------------------------------------------------
1159	hidnplayr	158	;
		159	;
1519	hidnplayr	160	;-----------------------------------------------------------------
1529	hidnplayr	161	macro TCP_timer_640ms {
1159	hidnplayr	162
1529	hidnplayr	163	local .loop
		164	local .exit
		165
1519	hidnplayr	166	; Update TCP sequence number
		167
1514	hidnplayr	168	add [TCP_sequence_num], 64000
1159	hidnplayr	169
1519	hidnplayr	170	; scan through all the active TCP sockets, decrementing ALL timers
		171	; timers do not have the chance to wrap because of the keepalive timer will kill the socket when it expires
1159	hidnplayr	172
1519	hidnplayr	173	mov eax, net_sockets
		174	.loop:
		175	mov eax, [eax + SOCKET.NextPtr]
		176	.check_only:
		177	or eax, eax
		178	jz .exit
1159	hidnplayr	179
1542	hidnplayr	180	cmp [eax + SOCKET.Protocol], IP_PROTO_TCP ;;; We should also check if family is AF_INET
1519	hidnplayr	181	jne .loop
1159	hidnplayr	182
1529	hidnplayr	183	inc [eax + TCP_SOCKET.t_idle]
		184	dec [eax + TCP_SOCKET.timer_retransmission]
1519	hidnplayr	185	jnz .check_more2
1254	hidnplayr	186
1519	hidnplayr	187	DEBUGF 1,"socket %x: Retransmission timer expired\n", eax
1159	hidnplayr	188
1519	hidnplayr	189	push eax
		190	call TCP_output
		191	pop eax
1159	hidnplayr	192
1519	hidnplayr	193	.check_more2:
		194	dec [eax + TCP_SOCKET.timer_keepalive]
		195	jnz .check_more3
1159	hidnplayr	196
1519	hidnplayr	197	DEBUGF 1,"socket %x: Keepalive expired\n", eax
1159	hidnplayr	198
1519	hidnplayr	199	;;; TODO: check socket state and handle accordingly
1318	hidnplayr	200
1519	hidnplayr	201	.check_more3:
		202	dec [eax + TCP_SOCKET.timer_timed_wait]
		203	jnz .check_more5
		204
		205	DEBUGF 1,"socket %x: 2MSL timer expired\n", eax
		206
		207	.check_more5:
		208	dec [eax + TCP_SOCKET.timer_persist]
		209	jnz .loop
		210
		211	DEBUGF 1,"socket %x: persist timer expired\n", eax
		212
		213	jmp .loop
		214	.exit:
1529	hidnplayr	215	}
1519	hidnplayr	216
		217
1529	hidnplayr	218
		219
		220	macro TCP_checksum IP1, IP2 {
		221
		222	;-------------
		223	; Pseudoheader
		224
		225	; protocol type
		226	mov edx, IP_PROTO_TCP
		227
		228	; source address
1530	hidnplayr	229	add dl, byte [IP1+1]
		230	adc dh, byte [IP1+0]
		231	adc dl, byte [IP1+3]
		232	adc dh, byte [IP1+2]
1529	hidnplayr	233
		234	; destination address
1530	hidnplayr	235	adc dl, byte [IP2+1]
		236	adc dh, byte [IP2+0]
		237	adc dl, byte [IP2+3]
		238	adc dh, byte [IP2+2]
1529	hidnplayr	239
		240	; size
		241	adc dl, cl
		242	adc dh, ch
		243
		244	;---------------------
		245	; Real header and data
		246
		247	push esi
		248	call checksum_1
		249	call checksum_2
		250	pop esi
		251
		252	} ; returns in dx only
		253
		254
1533	hidnplayr	255	macro TCP_sendseqinit ptr {
1529	hidnplayr	256
1533	hidnplayr	257	push edi ;;;; i dont like this static use of edi
		258	mov edi, [ptr + TCP_SOCKET.ISS]
		259	mov [ptr + TCP_SOCKET.SND_UP], edi
		260	mov [ptr + TCP_SOCKET.SND_MAX], edi
		261	mov [ptr + TCP_SOCKET.SND_NXT], edi
		262	mov [ptr + TCP_SOCKET.SND_UNA], edi
		263	pop edi
		264
		265	}
		266
		267	macro TCP_rcvseqinit ptr {
		268
		269	push edi
		270	mov edi, [ptr + TCP_SOCKET.IRS]
		271	inc edi
		272	mov [ptr + TCP_SOCKET.RCV_NXT], edi
		273	mov [ptr + TCP_SOCKET.RCV_ADV], edi
		274	pop edi
		275
		276	}
		277
		278
		279
1249	hidnplayr	280	;-----------------------------------------------------------------
		281	;
1514	hidnplayr	282	; TCP_input:
1159	hidnplayr	283	;
1514	hidnplayr	284	; IN: [esp] = ptr to buffer
		285	; [esp+4] = buffer size
		286	; ebx = ptr to device struct
		287	; ecx = segment size
		288	; edx = ptr to TCP segment
1196	hidnplayr	289	;
1514	hidnplayr	290	; esi = ipv4 source address
		291	; edi = ipv4 dest address
		292	;
1196	hidnplayr	293	; OUT: /
		294	;
		295	;-----------------------------------------------------------------
1249	hidnplayr	296	align 4
1514	hidnplayr	297	TCP_input:
1159	hidnplayr	298
1529	hidnplayr	299	DEBUGF 1,"TCP_input size=%u\n", ecx
1514	hidnplayr	300	; Offset must be greater than or equal to the size of the standard TCP header (20) and less than or equal to the TCP length.
1254	hidnplayr	301
1514	hidnplayr	302	movzx eax, [edx + TCP_segment.DataOffset]
		303	and eax, 0xf0
1529	hidnplayr	304	shr al, 2
1514	hidnplayr	305
1529	hidnplayr	306	DEBUGF 1,"headersize=%u\n", eax
1514	hidnplayr	307
		308	cmp eax, 20
		309	jl .drop
		310
		311	;-------------------------------
		312	; Now, re-calculate the checksum
		313
1529	hidnplayr	314	push eax ecx edx
		315	pushw [edx + TCP_segment.Checksum]
		316	mov [edx + TCP_segment.Checksum], 0
		317	push esi edi
1514	hidnplayr	318	mov esi, edx
1530	hidnplayr	319	TCP_checksum (esp), (esp+4)
1529	hidnplayr	320	pop esi edi ; yes, swap them (we dont need dest addr)
		321	pop cx ; previous checksum
		322	cmp cx, dx
		323	pop edx ecx esi
1514	hidnplayr	324	jnz .drop
		325
		326	DEBUGF 1,"Checksum is correct\n"
		327
1529	hidnplayr	328	sub ecx, esi ; update packet size
		329	jl .drop
1534	hidnplayr	330	DEBUGF 1,"we got %u bytes of data\n", ecx
1529	hidnplayr	331
1514	hidnplayr	332	;-----------------------------------------------------------------------------------------
		333	; Check if this packet has a timestamp option (We do it here so we can process it quickly)
		334
1529	hidnplayr	335	cmp esi, 20 + 12 ; Timestamp option is 12 bytes
1514	hidnplayr	336	jl .no_timestamp
		337	je .is_ok
		338
1529	hidnplayr	339	cmp byte [edx + TCP_segment.Data + 12], TCP_OPT_EOL ; end of option list
1514	hidnplayr	340	jne .no_timestamp
		341
		342	.is_ok:
		343	test [edx + TCP_segment.Flags], TH_SYN ; SYN flag must not be set
		344	jnz .no_timestamp
		345
		346	cmp dword [edx + TCP_segment.Data], 0x0101080a ; Timestamp header
		347	jne .no_timestamp
		348
		349	DEBUGF 1,"timestamp ok\n"
		350
1529	hidnplayr	351	; TODO: Parse the option
1514	hidnplayr	352	; TODO: Set a Bit in the TCP to tell all options are parsed
		353
		354	.no_timestamp:
		355
		356	;-------------------------------------------
		357	; Convert Big-endian values to little endian
		358
1543	hidnplayr	359	ntohd [edx + TCP_segment.SequenceNumber]
		360	ntohd [edx + TCP_segment.AckNumber]
1514	hidnplayr	361
1543	hidnplayr	362	ntohw [edx + TCP_segment.Window]
		363	ntohw [edx + TCP_segment.UrgentPointer]
		364	ntohw [edx + TCP_segment.SourcePort]
		365	ntohw [edx + TCP_segment.DestinationPort]
1514	hidnplayr	366
		367	;------------------------------------------------------------
		368	; Next thing to do is find the TCB (thus, the socket pointer)
		369
1274	hidnplayr	370	; IP Packet TCP Destination Port = local Port
1514	hidnplayr	371	; (IP Packet SenderAddress = Remote IP) OR (Remote IP = 0)
1318	hidnplayr	372	; (IP Packet TCP Source Port = remote Port) OR (remote Port = 0)
1159	hidnplayr	373
		374	mov ebx, net_sockets
		375
1249	hidnplayr	376	.socket_loop:
1514	hidnplayr	377	mov ebx, [ebx + SOCKET.NextPtr]
1159	hidnplayr	378	or ebx, ebx
1514	hidnplayr	379	jz .drop_with_reset
1159	hidnplayr	380
1543	hidnplayr	381	cmp [ebx + SOCKET.Domain], AF_INET4
1249	hidnplayr	382	jne .socket_loop
1159	hidnplayr	383
1543	hidnplayr	384	cmp [ebx + SOCKET.Protocol], IP_PROTO_TCP
		385	jne .socket_loop
		386
1514	hidnplayr	387	mov ax, [edx + TCP_segment.DestinationPort]
		388	cmp [ebx + TCP_SOCKET.LocalPort], ax
		389	jne .socket_loop
		390
		391	mov eax, [ebx + IP_SOCKET.RemoteIP]
1543	hidnplayr	392	cmp eax, edi ; edi is source ip from packet
1249	hidnplayr	393	je @f
		394	test eax, eax
1514	hidnplayr	395	jnz .socket_loop
1249	hidnplayr	396	@@:
1159	hidnplayr	397
1514	hidnplayr	398	mov ax, [ebx + TCP_SOCKET.RemotePort]
		399	cmp [edx + TCP_segment.SourcePort] , ax
1274	hidnplayr	400	je .found_socket
1249	hidnplayr	401	test ax, ax
1254	hidnplayr	402	jnz .socket_loop
1274	hidnplayr	403	.found_socket:
1529	hidnplayr	404	DEBUGF 1,"Socket ptr: %x\n", ebx
1254	hidnplayr	405
1514	hidnplayr	406	; ebx now contains the pointer to the socket
1257	hidnplayr	407
1514	hidnplayr	408	;----------------------------
		409	; Check if socket isnt closed
		410
1529	hidnplayr	411	cmp [ebx + TCP_SOCKET.t_state], TCB_CLOSED
1514	hidnplayr	412	je .drop
		413
		414	;----------------
		415	; Lock the socket
		416
1529	hidnplayr	417	;; add ebx, SOCKET.lock ; TODO: figure out if we should lock now already
		418	;; call wait_mutex
		419	;; sub ebx, SOCKET.lock
1159	hidnplayr	420
1529	hidnplayr	421	DEBUGF 1,"Socket locked\n"
1159	hidnplayr	422
1543	hidnplayr	423	;---------------------------------------
		424	; unscale the window into a 32 bit value
1529	hidnplayr	425
1514	hidnplayr	426	movzx eax, [edx + TCP_segment.Window]
1534	hidnplayr	427	push ecx
1529	hidnplayr	428	mov cl, [ebx + TCP_SOCKET.SND_SCALE]
1514	hidnplayr	429	shl eax, cl
1543	hidnplayr	430	mov dword [edx + TCP_segment.Window], eax ; word after window is checksum, we dont need checksum anymore
1534	hidnplayr	431	pop ecx
1514	hidnplayr	432
		433	;-----------------------------------
		434	; Is this socket a listening socket?
		435
1533	hidnplayr	436	test [ebx + SOCKET.options], SO_ACCEPTCON
1543	hidnplayr	437	jz .no_listening_socket
1514	hidnplayr	438
1543	hidnplayr	439	call SOCKET_fork
		440	jz .drop
		441
		442	push [edx + TCP_segment.DestinationPort]
		443	pop [eax + TCP_SOCKET.LocalPort]
		444
		445	push [edx - IPv4_Packet.DataOrOptional + IPv4_Packet.DestinationAddress] ;;; FIXME
		446	pop [eax + IP_SOCKET.LocalIP]
		447
		448	push [edx - IPv4_Packet.DataOrOptional + IPv4_Packet.SourceAddress] ;;; FIXME
		449	pop [eax + IP_SOCKET.RemoteIP]
		450
		451	mov [eax + TCP_SOCKET.t_state], TCB_LISTEN
		452
		453	jmp .not_uni_xfer
		454
		455	.no_listening_socket:
		456
1529	hidnplayr	457	;-------------------------------------
		458	; Reset idle timer and keepalive timer
1514	hidnplayr	459
1529	hidnplayr	460	mov [ebx + TCP_SOCKET.t_idle], 0
		461	mov [ebx + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval
1514	hidnplayr	462
1529	hidnplayr	463	;--------------------
		464	; Process TCP options
1514	hidnplayr	465
1529	hidnplayr	466	cmp esi, 20 ; esi is headersize
		467	je .no_options
1514	hidnplayr	468
1529	hidnplayr	469	DEBUGF 1,"Segment has options\n"
1514	hidnplayr	470
1530	hidnplayr	471	cmp [ebx + TCP_SOCKET.t_state], TCB_LISTEN ; no options when in listen state
1543	hidnplayr	472	jz .not_uni_xfer ; also no header prediction
1514	hidnplayr	473
1529	hidnplayr	474	lea edi, [edx + TCP_segment.Data]
		475	lea eax, [edx + esi]
1514	hidnplayr	476
1529	hidnplayr	477	.opt_loop:
		478	cmp edi, eax
		479	jge .no_options
1514	hidnplayr	480
1529	hidnplayr	481	cmp byte [edi], TCP_OPT_EOL ; end of option list?
		482	jz .no_options
1514	hidnplayr	483
1529	hidnplayr	484	cmp byte [edi], TCP_OPT_NOP ; nop ?
		485	jz .opt_nop
1514	hidnplayr	486
1529	hidnplayr	487	cmp byte [edi], TCP_OPT_MAXSEG
		488	je .opt_maxseg
1514	hidnplayr	489
1529	hidnplayr	490	cmp byte [edi], TCP_OPT_WINDOW
		491	je .opt_window
1514	hidnplayr	492
1529	hidnplayr	493	cmp byte [edi], TCP_OPT_TIMESTAMP
		494	je .opt_timestamp
1514	hidnplayr	495
1529	hidnplayr	496	jmp .no_options ; If we reach here, some unknown options were received, skip them all!
1514	hidnplayr	497
1529	hidnplayr	498	.opt_nop:
		499	inc edi
		500	jmp .opt_loop
1514	hidnplayr	501
1529	hidnplayr	502	.opt_maxseg:
		503	cmp byte [edi+1], 4
		504	jne .no_options ; error occured, ignore all options!
1514	hidnplayr	505
1529	hidnplayr	506	test [edx + TCP_segment.Flags], TH_SYN
		507	jz @f
		508
1530	hidnplayr	509	movzx eax, word[edi+2]
		510	rol ax, 8
1533	hidnplayr	511	DEBUGF 1,"Maxseg: %u\n", ax
1529	hidnplayr	512
1530	hidnplayr	513	mov [ebx + TCP_SOCKET.t_maxseg], eax
		514
1529	hidnplayr	515	@@:
		516	add edi, 4
		517	jmp .opt_loop
		518
		519
		520	.opt_window:
		521	cmp byte [edi+1], 3
		522	jne .no_options
		523
		524	test [edx + TCP_segment.Flags], TH_SYN
		525	jz @f
		526
1533	hidnplayr	527	DEBUGF 1,"Got window option\n"
1529	hidnplayr	528
		529	;;;;;
		530	@@:
		531	add edi, 3
		532	jmp .opt_loop
		533
		534
		535	.opt_timestamp:
		536	cmp byte [edi+1], 10
		537	jne .no_options
		538
1533	hidnplayr	539	DEBUGF 1,"Got timestamp option\n"
1529	hidnplayr	540
		541	;;;;;
		542
		543	add edi, 10
		544	jmp .opt_loop
		545
		546	.no_options:
		547
1514	hidnplayr	548	;-----------------------------------------------------------------------
		549	; Time to do some header prediction (Original Principle by Van Jacobson)
		550
		551	; There are two common cases for an uni-directional data transfer.
		552	;
		553	; General rule: the packets has no control flags, is in-sequence,
		554	; window width didnt change and we're not retransmitting.
		555	;
		556	; Second rules:
		557	; - If the length is 0 and the ACK moved forward, we're the sender side of the transfer.
		558	; In this case we'll free the ACK'ed data and notify higher levels that we have free space in buffer
		559	;
		560	; - If the length is not 0 and the ACK didn't move, we're the receiver side of the transfer.
		561	; If the packets are in order (data queue is empty), add the data to the socket buffer and request a delayed ACK
		562
1529	hidnplayr	563	cmp [ebx + TCP_SOCKET.t_state], TCB_ESTABLISHED
1514	hidnplayr	564	jnz .not_uni_xfer
		565
1529	hidnplayr	566	test [edx + TCP_segment.Flags], TH_SYN + TH_FIN + TH_RST + TH_URG
1514	hidnplayr	567	jnz .not_uni_xfer
		568
1529	hidnplayr	569	test [edx + TCP_segment.Flags], TH_ACK
1514	hidnplayr	570	jz .not_uni_xfer
		571
		572	mov eax, [edx + TCP_segment.SequenceNumber]
		573	cmp eax, [ebx + TCP_SOCKET.RCV_NXT]
		574	jne .not_uni_xfer
		575
1543	hidnplayr	576	mov eax, dword [edx + TCP_segment.Window]
1536	hidnplayr	577	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		578	jne .not_uni_xfer
1514	hidnplayr	579
		580	mov eax, [ebx + TCP_SOCKET.SND_NXT]
		581	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		582	jne .not_uni_xfer
		583
		584	;---------------------------------------
		585	; check if we are sender in the uni-xfer
		586
		587	; If the following 4 conditions are all true, this segment is a pure ACK.
		588	;
1529	hidnplayr	589	; - The segment contains no data.
		590	test ecx, ecx
1514	hidnplayr	591	jnz .not_sender
1274	hidnplayr	592
1529	hidnplayr	593	; - The congestion window is greater than or equal to the current send window.
1514	hidnplayr	594	; 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.
		595	mov eax, [ebx + TCP_SOCKET.SND_CWND]
		596	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		597	jl .not_uni_xfer
1318	hidnplayr	598
1529	hidnplayr	599	; - The acknowledgment field in the segment is less than or equal to the maximum sequence number sent.
1534	hidnplayr	600	mov eax, [edx + TCP_segment.AckNumber]
		601	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
1529	hidnplayr	602	jg .not_uni_xfer
		603
		604	; - The acknowledgment field in the segment is greater than the largest unacknowledged sequence number.
1534	hidnplayr	605	sub eax, [ebx + TCP_SOCKET.SND_UNA]
1529	hidnplayr	606	jle .not_uni_xfer
		607
1514	hidnplayr	608	DEBUGF 1,"Header prediction: we are sender\n"
1274	hidnplayr	609
1514	hidnplayr	610	;---------------------------------
		611	; Packet is a pure ACK, process it
1274	hidnplayr	612
1514	hidnplayr	613	; Update RTT estimators
1159	hidnplayr	614
1514	hidnplayr	615	; Delete acknowledged bytes from send buffer
1536	hidnplayr	616	mov ecx, eax
1533	hidnplayr	617	lea eax, [ebx + STREAM_SOCKET.snd]
1529	hidnplayr	618	call SOCKET_ring_free
		619
1536	hidnplayr	620	; update window pointers
		621	mov eax, [edx + TCP_segment.AckNumber]
		622	dec eax
		623	mov [ebx + TCP_SOCKET.SND_WL1], eax
		624
1514	hidnplayr	625	; Stop retransmit timer
1519	hidnplayr	626	mov [ebx + TCP_SOCKET.timer_ack], 0
1159	hidnplayr	627
1514	hidnplayr	628	; Awaken waiting processes
1519	hidnplayr	629	mov eax, ebx
		630	call SOCKET_notify_owner
1318	hidnplayr	631
1536	hidnplayr	632	;; Generate more output
		633	;; mov eax, ebx
		634	;; call TCP_output
		635	;;
		636	;; jmp .drop
		637	jmp .step6
1254	hidnplayr	638
1514	hidnplayr	639	;-------------------------------------------------
		640	; maybe we are the receiver in the uni-xfer then..
		641
		642	.not_sender:
1529	hidnplayr	643	; - The amount of data in the segment is greater than 0 (data count is in ecx)
1514	hidnplayr	644
1529	hidnplayr	645	; - The acknowledgment field equals the largest unacknowledged sequence number. This means no data is acknowledged by this segment.
1514	hidnplayr	646	mov eax, [edx + TCP_segment.AckNumber]
		647	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
		648	jne .not_uni_xfer
		649
1529	hidnplayr	650	; - The reassembly list of out-of-order segments for the connection is empty (seg_next equals tp). ;;;;;;;
1514	hidnplayr	651
		652	jnz .not_uni_xfer
		653
		654	;-------------------------------------
		655	; Complete processing of received data
		656
		657	DEBUGF 1,"header prediction: we are receiver\nreceiving %u bytes of data\n", ecx
		658
1529	hidnplayr	659	add esi, edx
1533	hidnplayr	660	lea eax, [ebx + STREAM_SOCKET.rcv]
		661	call SOCKET_ring_write ; Add the data to the socket buffer
1514	hidnplayr	662
1533	hidnplayr	663	mov eax, ebx
		664	call SOCKET_notify_owner
		665
1529	hidnplayr	666	add [ebx + TCP_SOCKET.RCV_NXT], ecx ; Update sequence number with number of bytes we have copied
		667	or [ebx + TCP_SOCKET.t_flags], TF_DELACK ; Set delayed ack flag
1514	hidnplayr	668
		669	jmp .drop
		670
		671	;----------------------------------------------------
1529	hidnplayr	672	; Header prediction failed, doing it the slow way.. ;;;;; current implementation of header prediction destroys some regs (ecx) !!
1514	hidnplayr	673
		674	.not_uni_xfer:
		675
1533	hidnplayr	676	DEBUGF 1,"Header prediction failed\n" ; time to do it the "slow" way :)
1514	hidnplayr	677
		678	;------------------------------
		679	; Calculate receive window size
		680
		681	;;;;
		682
1529	hidnplayr	683	cmp [ebx + TCP_SOCKET.t_state], TCB_LISTEN
1514	hidnplayr	684	je .LISTEN
		685
1529	hidnplayr	686	cmp [ebx + TCP_SOCKET.t_state], TCB_SYN_SENT
1514	hidnplayr	687	je .SYN_SENT
		688
		689	;--------------------------------------------
		690	; Protection Against Wrapped Sequence Numbers
		691
1533	hidnplayr	692	; First, check if timestamp is present
1514	hidnplayr	693
		694	;;;; TODO
		695
		696	; Then, check if at least some bytes of data are within window
		697
		698	;;;; TODO
		699
		700	jmp .trim_then_step6
		701
1529	hidnplayr	702	;-------------
		703	; Passive Open
		704
1249	hidnplayr	705	align 4
1514	hidnplayr	706	.LISTEN:
1196	hidnplayr	707
1514	hidnplayr	708	DEBUGF 1,"TCP state: listen\n"
1159	hidnplayr	709
1543	hidnplayr	710	test [edx + TCP_segment.Flags], TH_RST ;;; TODO: kill new socket on error
1514	hidnplayr	711	jnz .drop
1159	hidnplayr	712
1514	hidnplayr	713	test [edx + TCP_segment.Flags], TH_ACK
		714	jnz .drop_with_reset
1159	hidnplayr	715
1514	hidnplayr	716	test [edx + TCP_segment.Flags], TH_SYN
		717	jz .drop
1159	hidnplayr	718
1533	hidnplayr	719
1514	hidnplayr	720	; TODO: check if it's a broadcast or multicast, and drop if so
1159	hidnplayr	721
1529	hidnplayr	722	;-----------------------
		723	; Fill in some variables
1514	hidnplayr	724
1529	hidnplayr	725	add [TCP_sequence_num], 64000
1514	hidnplayr	726
1529	hidnplayr	727	push [edx + TCP_segment.SourcePort]
		728	pop [eax + TCP_SOCKET.RemotePort]
1514	hidnplayr	729
1529	hidnplayr	730	push [edx + TCP_segment.SequenceNumber]
		731	pop [eax + TCP_SOCKET.IRS]
1159	hidnplayr	732
1529	hidnplayr	733	push [eax + TCP_SOCKET.ISS]
		734	pop [eax + TCP_SOCKET.SND_NXT]
1159	hidnplayr	735
1543	hidnplayr	736	TCP_sendseqinit eax
		737	TCP_rcvseqinit eax
		738
1529	hidnplayr	739	mov [eax + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		740	mov [eax + TCP_SOCKET.t_flags], TF_ACKNOW
1543	hidnplayr	741	mov [eax + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval ;;;; macro
1159	hidnplayr	742
1543	hidnplayr	743	add eax, STREAM_SOCKET.snd
		744	call SOCKET_ring_create
		745
		746	add eax, STREAM_SOCKET.rcv - STREAM_SOCKET.snd
		747	call SOCKET_ring_create
		748
		749	sub eax, STREAM_SOCKET.rcv
		750
		751	mov [eax + SOCKET.lock], 0
		752	mov ebx, eax ; if there is data, it must arrive in this new socket!
1514	hidnplayr	753	jmp .trim_then_step6
1159	hidnplayr	754
1254	hidnplayr	755
1529	hidnplayr	756	;------------
		757	; Active Open
1159	hidnplayr	758
1514	hidnplayr	759	align 4
		760	.SYN_SENT:
1281	hidnplayr	761
1514	hidnplayr	762	DEBUGF 1,"TCP state: syn_sent\n"
1159	hidnplayr	763
1514	hidnplayr	764	test [edx + TCP_segment.Flags], TH_ACK
		765	jz @f
1281	hidnplayr	766
1514	hidnplayr	767	mov eax, [edx + TCP_segment.AckNumber]
		768	cmp eax, [ebx + TCP_SOCKET.ISS]
		769	jle .drop_with_reset
1281	hidnplayr	770
1529	hidnplayr	771	; mov eax, [edx + TCP_segment.AckNumber]
1533	hidnplayr	772	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		773	jg .drop_with_reset
1514	hidnplayr	774	@@:
1281	hidnplayr	775
1514	hidnplayr	776	test [edx + TCP_segment.Flags], TH_RST
		777	jz @f
1281	hidnplayr	778
1514	hidnplayr	779	test [edx + TCP_segment.Flags], TH_ACK
		780	jz .drop
1281	hidnplayr	781
1716	hidnplayr	782	mov ebx, ECONNREFUSED
		783	call TCP_drop
1159	hidnplayr	784
1514	hidnplayr	785	jmp .drop
		786	@@:
1159	hidnplayr	787
1514	hidnplayr	788	test [edx + TCP_segment.Flags], TH_SYN
		789	jz .drop
1318	hidnplayr	790
1529	hidnplayr	791	; at this point, segment seems to be valid
		792
1514	hidnplayr	793	test [edx + TCP_segment.Flags], TH_ACK
1529	hidnplayr	794	jz .no_syn_ack
1514	hidnplayr	795
1529	hidnplayr	796	; now, process received SYN in response to an active open
		797
1514	hidnplayr	798	mov eax, [edx + TCP_segment.AckNumber]
		799	mov [ebx + TCP_SOCKET.SND_UNA], eax
		800	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		801	jle @f
		802	mov [ebx + TCP_SOCKET.SND_NXT], eax
1529	hidnplayr	803	@@:
1514	hidnplayr	804
1529	hidnplayr	805	.no_syn_ack:
1514	hidnplayr	806
1529	hidnplayr	807	mov [ebx + TCP_SOCKET.timer_retransmission], 0 ; disable retransmission
1514	hidnplayr	808
1529	hidnplayr	809	push [edx + TCP_segment.SequenceNumber]
		810	pop [ebx + TCP_SOCKET.IRS]
		811
1533	hidnplayr	812	TCP_rcvseqinit ebx
1529	hidnplayr	813
		814	mov [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
		815
		816	mov eax, [ebx + TCP_SOCKET.SND_UNA]
		817	cmp eax, [ebx + TCP_SOCKET.ISS]
		818	jle .simultaneous_open
		819
		820	test [edx + TCP_segment.Flags], TH_ACK
		821	jz .simultaneous_open
		822
		823	DEBUGF 1,"TCP: active open\n"
		824
		825	; TODO: update stats
1533	hidnplayr	826	; TODO: set general socket state to connected
1514	hidnplayr	827
		828	mov [ebx + TCP_SOCKET.t_state], TCB_ESTABLISHED
		829
		830	; TODO: check if we should scale the connection (567-572)
		831	; TODO: update RTT estimators
		832
1529	hidnplayr	833	jmp .trimthenstep6
1514	hidnplayr	834
1529	hidnplayr	835	.simultaneous_open:
1514	hidnplayr	836
1529	hidnplayr	837	DEBUGF 1,"TCP: simultaneous open\n"
1514	hidnplayr	838	; We have received a syn but no ACK, so we are having a simultaneous open..
		839	mov [ebx + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		840
		841	;-------------------------------------
		842	; Common processing for receipt of SYN
		843
		844	.trimthenstep6:
		845
		846	inc [edx + TCP_segment.SequenceNumber]
		847
		848	cmp cx, [ebx + TCP_SOCKET.RCV_WND]
		849	jle @f
		850
		851	movzx eax, cx
		852	sub ax, [ebx + TCP_SOCKET.RCV_WND]
		853	; TODO: 592
		854	mov cx, [ebx + TCP_SOCKET.RCV_WND]
		855	; TODO...
		856	@@:
		857	;;;;;
1529	hidnplayr	858	jmp .step6
1514	hidnplayr	859
		860
1529	hidnplayr	861	.trim_then_step6:
1159	hidnplayr	862
1514	hidnplayr	863	;----------------------------
		864	; trim any data not in window
1159	hidnplayr	865
1533	hidnplayr	866	DEBUGF 1,"Trimming window\n"
		867
1514	hidnplayr	868	mov eax, [ebx + TCP_SOCKET.RCV_NXT]
		869	sub eax, [edx + TCP_segment.SequenceNumber]
1318	hidnplayr	870
1514	hidnplayr	871	test eax, eax
1533	hidnplayr	872	jz .no_duplicate
1274	hidnplayr	873
1514	hidnplayr	874	test [edx + TCP_segment.Flags], TH_SYN
		875	jz .no_drop
		876
		877	and [edx + TCP_segment.Flags], not (TH_SYN)
		878	inc [edx + TCP_segment.SequenceNumber]
		879
		880	cmp [edx + TCP_segment.UrgentPointer], 1
		881	jl @f
		882
		883	dec [edx + TCP_segment.UrgentPointer]
		884
		885	jmp .no_drop
		886	@@:
		887
		888	and [edx + TCP_segment.Flags], not (TH_URG)
		889	dec eax
1533	hidnplayr	890	jz .no_duplicate
1514	hidnplayr	891	.no_drop:
		892
1533	hidnplayr	893	DEBUGF 1,"Going to drop %u out of %u bytes\n", eax, ecx
1529	hidnplayr	894
1514	hidnplayr	895	; eax holds number of bytes to drop
		896
		897	;----------------------------------
		898	; Check for entire duplicate packet
		899
		900	cmp eax, ecx
		901	jge .duplicate
		902
		903	;;; TODO: figure 28.30
		904
		905	;------------------------
		906	; Check for duplicate FIN
		907
		908	test [edx + TCP_segment.Flags], TH_FIN
		909	jz @f
		910	inc ecx
		911	cmp eax, ecx
		912	dec ecx
		913	jne @f
		914
		915	mov eax, ecx
		916	and [edx + TCP_segment.Flags], not TH_FIN
1529	hidnplayr	917	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1514	hidnplayr	918	jmp .no_duplicate
		919	@@:
		920
		921	; Handle the case when a bound socket connects to itself
		922	; Allow packets with a SYN and an ACKto continue with the processing
		923
		924	;-------------------------------------
		925	; Generate duplicate ACK if nescessary
		926
		927	; This code also handles simultaneous half-open or self-connects
		928
		929	test eax, eax
		930	jnz .drop_after_ack
		931
		932	cmp [edx + TCP_segment.Flags], TH_ACK
		933	jz .drop_after_ack
		934
		935	.duplicate:
		936
1533	hidnplayr	937	DEBUGF 1,"Duplicate received\n"
1529	hidnplayr	938
1514	hidnplayr	939	;----------------------------------------
		940	; Update statistics for duplicate packets
		941
		942	;;; TODO
		943
1529	hidnplayr	944	jmp .drop ;;; DROP the packet ??
1514	hidnplayr	945
		946	.no_duplicate:
		947
		948	;-----------------------------------------------
		949	; Remove duplicate data and update urgent offset
		950
		951	add [edx + TCP_segment.SequenceNumber], eax
		952
		953	;;; TODO
		954
		955	sub [edx + TCP_segment.UrgentPointer], ax
		956	jg @f
		957
		958	and [edx + TCP_segment.Flags], not (TH_URG)
		959	mov [edx + TCP_segment.UrgentPointer], 0
		960	@@:
		961
		962	;--------------------------------------------------
		963	; Handle data that arrives after process terminates
		964
		965	cmp [ebx + SOCKET.PID], 0
1533	hidnplayr	966	jg @f
1514	hidnplayr	967
		968	cmp [ebx + TCP_SOCKET.t_state], TCB_CLOSE_WAIT
		969	jle @f
		970
		971	test ecx, ecx
		972	jz @f
		973
		974	;;; Close the socket
		975	;;; update stats
		976
		977	jmp .drop_with_reset
		978	@@:
		979
		980	;----------------------------------------
		981	; Remove data beyond right edge of window
		982
		983	mov eax, [edx + TCP_segment.SequenceNumber]
		984	add eax, ecx
		985	sub eax, [ebx + TCP_SOCKET.RCV_NXT]
		986	sub ax, [ebx + TCP_SOCKET.RCV_WND]
		987
		988	; eax now holds the number of bytes to drop
		989
		990	jle .no_excess_data
		991
		992	;;; TODO: update stats
		993
		994	cmp eax, ecx
		995	jl .dont_drop_all
		996
		997	;;; TODO 700-736
		998
		999	.dont_drop_all:
		1000
		1001	.no_excess_data:
		1002
		1003	;-----------------
		1004	; Record timestamp
		1005
		1006	;;; TODO 737-746
		1007
		1008	;------------------
		1009	; Process RST flags
		1010
		1011	test [edx + TCP_segment.Flags], TH_RST
		1012	jz .rst_skip
		1013
1529	hidnplayr	1014	DEBUGF 1,"Got an RST flag"
		1015
1514	hidnplayr	1016	mov eax, [ebx + TCP_SOCKET.t_state]
		1017	shl eax, 2
		1018	jmp dword [eax + .rst_sw_list]
		1019
		1020	.rst_sw_list:
		1021	dd .rst_skip ;TCB_CLOSED
		1022	dd .rst_skip ;TCB_LISTEN
		1023	dd .rst_skip ;TCB_SYN_SENT
		1024	dd .econnrefused ;TCB_SYN_RECEIVED
		1025	dd .econnreset ;TCB_ESTABLISHED
		1026	dd .econnreset ;TCB_CLOSE_WAIT
		1027	dd .econnreset ;TCB_FIN_WAIT_1
		1028	dd .rst_close ;TCB_CLOSING
		1029	dd .rst_close ;TCB_LAST_ACK
		1030	dd .econnreset ;TCB_FIN_WAIT_2
		1031	dd .rst_close ;TCB_TIMED_WAIT
		1032
		1033	.econnrefused:
		1034
1529	hidnplayr	1035	DEBUGF 1,"Connection refused"
		1036
1514	hidnplayr	1037	;;; TODO: debug info
		1038
		1039	jmp .close
		1040
		1041	.econnreset:
		1042
1529	hidnplayr	1043	DEBUGF 1,"Connection reset"
		1044
1514	hidnplayr	1045	;;; TODO: debug info
1529	hidnplayr	1046	.close:
1514	hidnplayr	1047
1529	hidnplayr	1048	DEBUGF 1,"Closing connection"
		1049
1514	hidnplayr	1050	;;; update stats
		1051
		1052	.rst_close:
		1053
1534	hidnplayr	1054	DEBUGF 1,"Closing with reset\n"
1529	hidnplayr	1055
1514	hidnplayr	1056	;;; Close the socket
		1057	jmp .drop
		1058
		1059	.rst_skip:
		1060
		1061	;--------------------------------------
		1062	; handle SYN-full and ACK-less segments
		1063
		1064	test [edx + TCP_segment.Flags], TH_SYN
		1065	jz @f
		1066
1716	hidnplayr	1067	mov ebx, ECONNRESET
		1068	call TCP_drop
		1069
1514	hidnplayr	1070	jmp .drop_with_reset
		1071
		1072	test [edx + TCP_segment.Flags], TH_ACK
		1073	jz .drop
1534	hidnplayr	1074	@@:
1514	hidnplayr	1075	;----------------
		1076	; Process the ACK
		1077
		1078	cmp [ebx + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		1079	jg .ack_dup
		1080	jl .ack_nodup
		1081
1534	hidnplayr	1082	DEBUGF 1,"TCP state = syn received\n"
1533	hidnplayr	1083
1514	hidnplayr	1084	;;;;;
		1085
1536	hidnplayr	1086	.ack_nodup:
1514	hidnplayr	1087
1536	hidnplayr	1088	DEBUGF 1,"New ACK\n"
1533	hidnplayr	1089
1514	hidnplayr	1090
		1091
1536	hidnplayr	1092	.ack_dup:
1514	hidnplayr	1093
1536	hidnplayr	1094	;;;;
1533	hidnplayr	1095
1514	hidnplayr	1096	;-------------------------------------------------
1519	hidnplayr	1097	; If the congestion window was inflated to account
1514	hidnplayr	1098	; for the other side's cached packets, retrace it
		1099
		1100	;;;; 888 - 902
		1101
		1102
		1103	;------------------------------------------
		1104	; RTT measurements and retransmission timer
		1105
		1106	;;;;; 903 - 926
		1107
1519	hidnplayr	1108	mov [ebx + TCP_SOCKET.timer_retransmission], 0
1514	hidnplayr	1109
1519	hidnplayr	1110	mov eax, [ebx + TCP_SOCKET.SND_MAX]
		1111	cmp eax, [edx + TCP_segment.AckNumber]
		1112	je .all_outstanding
1543	hidnplayr	1113	mov [ebx + TCP_SOCKET.timer_retransmission], 120 ;;;; TODO: correct this value (use a macro for it)
1519	hidnplayr	1114	.all_outstanding:
		1115
1514	hidnplayr	1116	;-------------------------------------------
		1117	; Open congestion window in response to ACKs
		1118
		1119	;;;;
		1120
		1121
		1122	;------------------------------------------
		1123	; Remove acknowledged data from send buffer
		1124
1536	hidnplayr	1125	pusha
		1126	; Delete acknowledged bytes from send buffer
		1127	mov ecx, [edx + TCP_segment.AckNumber]
		1128	sub ecx, [ebx + TCP_SOCKET.SND_UNA]
1533	hidnplayr	1129	lea eax, [ebx + STREAM_SOCKET.snd]
1536	hidnplayr	1130	call SOCKET_ring_free
		1131	popa
1514	hidnplayr	1132
1536	hidnplayr	1133
		1134	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; code missing (943?)
		1135
1542	hidnplayr	1136
		1137
1536	hidnplayr	1138	mov eax, [edx + TCP_segment.AckNumber]
		1139	mov [ebx + TCP_SOCKET.SND_UNA], eax
		1140
		1141	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		1142	jl @f
		1143	mov [ebx + TCP_SOCKET.SND_NXT], eax
		1144	@@:
		1145
		1146
1514	hidnplayr	1147	;---------------------------------------
		1148	; Wake up process waiting on send buffer
		1149
1529	hidnplayr	1150	mov eax, ebx
		1151	call SOCKET_notify_owner
1514	hidnplayr	1152
		1153	mov eax, [ebx + TCP_SOCKET.t_state]
		1154	shl eax, 2
		1155	jmp dword [eax + .ACK_sw_list]
		1156
		1157	.ACK_sw_list:
		1158	dd .step6 ;TCB_CLOSED
		1159	dd .step6 ;TCB_LISTEN
		1160	dd .step6 ;TCB_SYN_SENT
		1161	dd .step6 ;TCB_SYN_RECEIVED
		1162	dd .step6 ;TCB_ESTABLISHED
		1163	dd .step6 ;TCB_CLOSE_WAIT
		1164	dd ._963 ;TCB_FIN_WAIT_1
		1165	dd ._958 ;TCB_CLOSING
		1166	dd ._999 ;TCB_LAST_ACK
		1167	dd .step6 ;TCB_FIN_WAIT_2
		1168	dd ._1010 ;TCB_TIMED_WAIT
		1169
		1170
1536	hidnplayr	1171	._963:
1514	hidnplayr	1172
		1173
		1174	jmp .step6
		1175
		1176
1536	hidnplayr	1177	._958:
1514	hidnplayr	1178
		1179	jmp .step6
		1180
1536	hidnplayr	1181	._999:
1514	hidnplayr	1182
		1183	jmp .step6
		1184
		1185
1536	hidnplayr	1186	._1010:
1514	hidnplayr	1187
		1188	jmp .step6
		1189
		1190
1536	hidnplayr	1191	.step6:
1514	hidnplayr	1192
		1193	DEBUGF 1,"step 6\n"
		1194
1536	hidnplayr	1195	;----------------------------------------------
		1196	; check if we need to update window information
1514	hidnplayr	1197
		1198	test [edx + TCP_segment.Flags], TH_ACK
		1199	jz .no_window_update
		1200
		1201	mov eax, [ebx + TCP_SOCKET.SND_WL1]
		1202	cmp eax, [edx + TCP_segment.SequenceNumber]
1536	hidnplayr	1203	jl .update_window
		1204	jg @f
1514	hidnplayr	1205
		1206	mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1207	cmp eax, [edx + TCP_segment.AckNumber]
1536	hidnplayr	1208	jl .update_window
		1209	jg .no_window_update
		1210	@@:
1514	hidnplayr	1211
1543	hidnplayr	1212	mov eax, [ebx + TCP_SOCKET.SND_WL2]
1536	hidnplayr	1213	cmp eax, [edx + TCP_segment.AckNumber]
		1214	jne .no_window_update
		1215
		1216	movzx eax, [edx + TCP_segment.Window]
1514	hidnplayr	1217	cmp eax, [ebx + TCP_SOCKET.SND_WND]
1536	hidnplayr	1218	jle .no_window_update
1514	hidnplayr	1219
1536	hidnplayr	1220	.update_window:
1514	hidnplayr	1221
1536	hidnplayr	1222	DEBUGF 1,"Updating window\n"
1514	hidnplayr	1223
1536	hidnplayr	1224	;----------------------------------
		1225	; Keep track of pure window updates
		1226
		1227	; test ecx, ecx
		1228	; jz @f
		1229	;
		1230	; mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1231	; cmp eax, [edx + TCP_segment.AckNumber]
		1232	; jne @f
		1233	;
		1234	; ;; mov eax, tiwin
		1235	; cmp eax, [ebx + TCP_SOCKET.SND_WND]
		1236	; jle @f
		1237	;
		1238	; ;;; update stats
		1239	;
		1240	; @@:
		1241
1543	hidnplayr	1242	mov eax, dword [edx + TCP_segment.Window]
1514	hidnplayr	1243	cmp eax, [ebx + TCP_SOCKET.max_sndwnd]
		1244	jle @f
		1245	mov [ebx + TCP_SOCKET.max_sndwnd], eax
		1246	@@:
		1247	mov [ebx + TCP_SOCKET.SND_WND], eax
		1248
1536	hidnplayr	1249	push [edx + TCP_segment.SequenceNumber]
		1250	pop [ebx + TCP_SOCKET.SND_WL1]
1514	hidnplayr	1251
1536	hidnplayr	1252	push [edx + TCP_segment.AckNumber]
		1253	pop [ebx + TCP_SOCKET.SND_WL2]
1514	hidnplayr	1254
		1255	;;; needoutput = 1
		1256
		1257	.no_window_update:
		1258
		1259	;-----------------
		1260	; process URG flag
		1261
		1262	test [edx + TCP_segment.Flags], TH_URG
		1263	jz .not_urgent
		1264
		1265	cmp [edx + TCP_segment.UrgentPointer], 0
		1266	jz .not_urgent
		1267
		1268	cmp [ebx + TCP_SOCKET.t_state], TCB_TIMED_WAIT
		1269	je .not_urgent
		1270
		1271	; Ignore bogus urgent offsets
		1272
		1273	;;; 1040-1050
		1274
		1275	movzx eax, [edx + TCP_segment.UrgentPointer]
1533	hidnplayr	1276	add eax, [ebx + STREAM_SOCKET.rcv + RING_BUFFER.size]
1514	hidnplayr	1277	cmp eax, SOCKET_MAXDATA
		1278	jle .not_urgent
		1279
		1280	mov [edx + TCP_segment.UrgentPointer], 0
		1281	and [edx + TCP_segment.Flags], not (TH_URG)
		1282	jmp .do_data
		1283
		1284	.not_urgent:
		1285
		1286	;--------------------------------------
		1287	; processing of received urgent pointer
		1288
1529	hidnplayr	1289	;;; TODO (1051-1093)
1514	hidnplayr	1290
1529	hidnplayr	1291	;--------------------------------
		1292	; process the data in the segment
1514	hidnplayr	1293
1529	hidnplayr	1294	.do_data:
1514	hidnplayr	1295
1534	hidnplayr	1296	DEBUGF 1,"TCP: do data (%u)\n", ecx
1514	hidnplayr	1297
		1298	test [edx + TCP_segment.Flags], TH_FIN
1529	hidnplayr	1299	jnz .process_fin
1514	hidnplayr	1300
1533	hidnplayr	1301	cmp [ebx + TCP_SOCKET.t_state], TCB_FIN_WAIT_1
1514	hidnplayr	1302	jge .dont_do_data
		1303
1533	hidnplayr	1304	test ecx, ecx
		1305	jz .final_processing
		1306
1514	hidnplayr	1307	DEBUGF 1,"Processing data in segment\n"
		1308
1533	hidnplayr	1309	;; TODO: check if data is in sequence !
1514	hidnplayr	1310
1533	hidnplayr	1311	movzx eax, [edx + TCP_segment.DataOffset] ;;; todo: remember this in.. edi ?
		1312	and eax, 0xf0
		1313	shr al, 2
		1314
		1315	lea esi, [edx + eax]
		1316
		1317	or [ebx + TCP_SOCKET.t_flags], TF_DELACK
1543	hidnplayr	1318	add [ebx + TCP_SOCKET.RCV_NXT], ecx
1533	hidnplayr	1319
		1320	lea eax, [ebx + STREAM_SOCKET.rcv]
		1321	call SOCKET_ring_write
		1322
		1323	mov eax, ebx
		1324	call SOCKET_notify_owner
		1325
1514	hidnplayr	1326	jmp .final_processing
		1327
		1328
		1329	.dont_do_data:
		1330
		1331	;---------------
		1332	; FIN processing
		1333
		1334	.process_fin:
		1335
		1336	DEBUGF 1,"Processing FIN\n"
		1337
		1338	mov eax, [ebx + TCP_SOCKET.t_state]
		1339	shl eax, 2
		1340	jmp dword [eax + .FIN_sw_list]
		1341
		1342	.FIN_sw_list:
		1343	dd .no_fin ;TCB_CLOSED
		1344	dd .no_fin ;TCB_LISTEN
		1345	dd .no_fin ;TCB_SYN_SENT
1533	hidnplayr	1346	dd .fin_syn_est ;TCB_SYN_RECEIVED
		1347	dd .fin_syn_est ;TCB_ESTABLISHED
1514	hidnplayr	1348	dd .no_fin ;TCB_CLOSE_WAIT
1533	hidnplayr	1349	dd .fin_wait1 ;TCB_FIN_WAIT_1
1514	hidnplayr	1350	dd .no_fin ;TCB_CLOSING
		1351	dd .no_fin ;TCB_LAST_ACK
1533	hidnplayr	1352	dd .fin_wait2 ;TCB_FIN_WAIT_2
		1353	dd .fin_timed ;TCB_TIMED_WAIT
1514	hidnplayr	1354
		1355
		1356
1533	hidnplayr	1357	.fin_syn_est:
1514	hidnplayr	1358
1533	hidnplayr	1359	jmp .final_processing
1514	hidnplayr	1360
1533	hidnplayr	1361	.fin_wait1:
1514	hidnplayr	1362
1533	hidnplayr	1363	jmp .final_processing
1514	hidnplayr	1364
1533	hidnplayr	1365	.fin_wait2:
1514	hidnplayr	1366
1533	hidnplayr	1367	jmp .final_processing
		1368
		1369	.fin_timed:
		1370
		1371	jmp .final_processing
		1372
1514	hidnplayr	1373	.no_fin:
		1374
		1375	;-----------------
		1376	; Final processing
		1377
		1378	.final_processing:
		1379
		1380	DEBUGF 1,"Final processing\n"
		1381
1533	hidnplayr	1382	mov [ebx + SOCKET.lock], 0
		1383
1514	hidnplayr	1384	;;; if debug enabled, output packet
		1385
		1386	;test ;;;needoutput = 1
		1387	;jnz .outputnow
		1388
		1389	test [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1529	hidnplayr	1390	jnz .ack_now
1514	hidnplayr	1391
1529	hidnplayr	1392	call kernel_free
		1393	add esp, 4
		1394	ret
		1395
		1396	.ack_now:
		1397
		1398	DEBUGF 1,"ACK now!\n"
		1399
		1400	push ebx
		1401	mov eax, ebx
1514	hidnplayr	1402	call TCP_output
1529	hidnplayr	1403	pop ebx
1514	hidnplayr	1404
1274	hidnplayr	1405	call kernel_free
1529	hidnplayr	1406	add esp, 4
		1407	ret
1274	hidnplayr	1408
1514	hidnplayr	1409	;------------------------------------------
		1410	; Generate an ACK, droping incoming segment
1274	hidnplayr	1411
1514	hidnplayr	1412	align 4
		1413	.drop_after_ack:
1274	hidnplayr	1414
1514	hidnplayr	1415	DEBUGF 1,"Drop after ACK\n"
1274	hidnplayr	1416
1514	hidnplayr	1417	test [edx + TCP_segment.Flags], TH_RST
		1418	jnz .drop
1274	hidnplayr	1419
1514	hidnplayr	1420	and [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1274	hidnplayr	1421
1529	hidnplayr	1422	push ebx
		1423	mov eax, ebx
1514	hidnplayr	1424	call TCP_output
1529	hidnplayr	1425	pop ebx
1318	hidnplayr	1426
1514	hidnplayr	1427	call kernel_free
1529	hidnplayr	1428	add esp, 4
		1429	ret
1274	hidnplayr	1430
1514	hidnplayr	1431
		1432	;-------------------------------------------
		1433	; Generate an RST, dropping incoming segment
		1434
		1435	align 4
		1436	.drop_with_reset:
		1437
		1438	DEBUGF 1,"Drop with reset\n"
		1439
		1440	test [edx + TCP_segment.Flags], TH_RST
		1441	jnz .drop
		1442
		1443	;;; if its a multicast/broadcast, also drop
		1444
		1445	test [edx + TCP_segment.Flags], TH_ACK
		1446	jnz .respond_ack
		1447
		1448	test [edx + TCP_segment.Flags], TH_SYN
		1449	jnz .respond_syn
		1450
		1451	call kernel_free
1529	hidnplayr	1452	add esp, 4
		1453	ret
1514	hidnplayr	1454
		1455	.respond_ack:
		1456
1533	hidnplayr	1457	mov dl, TH_RST
1514	hidnplayr	1458
1533	hidnplayr	1459	push ebx
1529	hidnplayr	1460	call TCP_respond_segment
1533	hidnplayr	1461	pop ebx
1514	hidnplayr	1462
		1463	jmp .destroy_new_socket
		1464
		1465
		1466	.respond_syn:
		1467
1533	hidnplayr	1468	mov dl, TH_RST + TH_ACK
1514	hidnplayr	1469
1533	hidnplayr	1470	push ebx
		1471	call TCP_respond_socket
		1472	pop ebx
1514	hidnplayr	1473
		1474	jmp .destroy_new_socket
		1475
		1476	;-----
		1477	; Drop
		1478
		1479	align 4
		1480	.drop:
		1481
		1482	DEBUGF 1,"Dropping packet\n"
		1483
		1484	;;;; If debugging options are enabled, output the packet somwhere
		1485
		1486	.destroy_new_socket:
		1487
		1488	;;;; kill the newly created socket
		1489
		1490	call kernel_free
1529	hidnplayr	1491	add esp, 4
		1492	ret
1514	hidnplayr	1493
		1494
		1495
		1496
		1497
		1498
		1499	;---------------------------
		1500	;
		1501	; TCP_pull_out_of_band
		1502	;
		1503	; IN: eax =
		1504	; ebx = socket ptr
		1505	; edx = tcp packet ptr
		1506	;
		1507	; OUT: /
		1508	;
		1509	;---------------------------
		1510
		1511	align 4
		1512	TCP_pull_out_of_band:
		1513
		1514	DEBUGF 1,"TCP_pull_out_of_band\n"
		1515
		1516	;;;; 1282-1305
		1517
1318	hidnplayr	1518	ret
		1519
		1520
		1521
		1522	;-----------------------------------------------------------------
		1523	;
1514	hidnplayr	1524	; TCP_output
1318	hidnplayr	1525	;
1519	hidnplayr	1526	; IN: eax = socket pointer
1514	hidnplayr	1527	;
1318	hidnplayr	1528	; OUT: /
		1529	;
		1530	;-----------------------------------------------------------------
		1531	align 4
1514	hidnplayr	1532	TCP_output:
1318	hidnplayr	1533
1514	hidnplayr	1534	DEBUGF 1,"TCP_output, socket: %x\n", eax
1318	hidnplayr	1535
1514	hidnplayr	1536	; We'll detect the length of the data to be transmitted, and flags to be used
		1537	; If there is some data, or any critical controls to send (SYN / RST), then transmit
		1538	; Otherwise, investigate further
1318	hidnplayr	1539
1514	hidnplayr	1540	mov ebx, [eax + TCP_SOCKET.SND_MAX]
		1541	cmp ebx, [eax + TCP_SOCKET.SND_UNA]
		1542	jne .not_idle
1318	hidnplayr	1543
1514	hidnplayr	1544	mov ebx, [eax + TCP_SOCKET.t_idle]
		1545	cmp ebx, [eax + TCP_SOCKET.t_rxtcur]
		1546	jle .not_idle
1318	hidnplayr	1547
1514	hidnplayr	1548	; We have been idle for a while and no ACKS are expected to clock out any data we send..
		1549	; Slow start to get ack "clock" running again.
1318	hidnplayr	1550
1514	hidnplayr	1551	mov ebx, [eax + TCP_SOCKET.t_maxseg]
		1552	mov [eax + TCP_SOCKET.SND_CWND], ebx
1318	hidnplayr	1553
1514	hidnplayr	1554	.not_idle:
		1555	.again:
		1556	mov ebx, [eax + TCP_SOCKET.SND_NXT] ; calculate offset
		1557	sub ebx, [eax + TCP_SOCKET.SND_UNA] ;
1318	hidnplayr	1558
1514	hidnplayr	1559	mov ecx, [eax + TCP_SOCKET.SND_WND] ; determine window
		1560	cmp ecx, [eax + TCP_SOCKET.SND_CWND] ;
		1561	jl @f ;
		1562	mov ecx, [eax + TCP_SOCKET.SND_CWND] ;
		1563	@@: ;
1318	hidnplayr	1564
1529	hidnplayr	1565	call TCP_outflags ; in dl
1318	hidnplayr	1566
1514	hidnplayr	1567	; If in persist timeout with window of 0, send 1 byte.
		1568	; Otherwise, if window is small but nonzero, and timer expired,
		1569	; we will send what we can and go to transmit state
1318	hidnplayr	1570
1514	hidnplayr	1571	test [eax + TCP_SOCKET.t_force], -1
		1572	jz .no_persist_timeout
1318	hidnplayr	1573
1514	hidnplayr	1574	test ecx, ecx
		1575	jnz .no_zero_window
1255	hidnplayr	1576
1533	hidnplayr	1577	cmp ebx, [eax + STREAM_SOCKET.snd + RING_BUFFER.size]
1514	hidnplayr	1578	jge @f
1255	hidnplayr	1579
1514	hidnplayr	1580	and dl, not (TH_FIN) ; clear the FIN flag ??? how can it be set before?
1255	hidnplayr	1581
1514	hidnplayr	1582	@@:
		1583	inc ecx
		1584	jmp .no_persist_timeout
1255	hidnplayr	1585
1514	hidnplayr	1586	.no_zero_window:
1254	hidnplayr	1587
1543	hidnplayr	1588	mov [eax + TCP_SOCKET.timer_persist], 0
1514	hidnplayr	1589	mov [eax + TCP_SOCKET.t_rxtshift], 0
1254	hidnplayr	1590
1514	hidnplayr	1591	.no_persist_timeout:
1159	hidnplayr	1592
1514	hidnplayr	1593	;;;106
1159	hidnplayr	1594
1533	hidnplayr	1595	mov esi, [eax + STREAM_SOCKET.snd + RING_BUFFER.size]
1514	hidnplayr	1596	cmp esi, ecx
		1597	jl @f
		1598	mov esi, ecx
		1599	@@:
		1600	sub esi, ebx
1254	hidnplayr	1601
1514	hidnplayr	1602	cmp esi, -1
		1603	jne .not_minus_one
1159	hidnplayr	1604
1514	hidnplayr	1605	; If FIN has been set, but not ACKed, and we havent been called to retransmit,
		1606	; len (esi) will be -1
		1607	; Otherwise, window shrank after we sent into it.
		1608	; If window shrank to 0, cancel pending retransmit and pull SND_NXT back to (closed) window
		1609	; We will enter persist state below.
		1610	; If window didn't close completely, just wait for an ACK
1159	hidnplayr	1611
1514	hidnplayr	1612	xor esi, esi
1159	hidnplayr	1613
1514	hidnplayr	1614	test ecx, ecx
		1615	jnz @f
1159	hidnplayr	1616
1529	hidnplayr	1617	mov [eax + TCP_SOCKET.timer_retransmission], 0 ; cancel retransmit
1274	hidnplayr	1618
1514	hidnplayr	1619	push [eax + TCP_SOCKET.SND_UNA]
		1620	pop [eax + TCP_SOCKET.SND_NXT]
		1621	@@:
1254	hidnplayr	1622
1514	hidnplayr	1623	.not_minus_one:
1254	hidnplayr	1624
1514	hidnplayr	1625	;;; 124
1159	hidnplayr	1626
1514	hidnplayr	1627	cmp esi, [eax + TCP_SOCKET.t_maxseg]
		1628	jle @f
1274	hidnplayr	1629
1514	hidnplayr	1630	mov esi, [eax + TCP_SOCKET.t_maxseg]
		1631	;sendalot = 1
1274	hidnplayr	1632
1514	hidnplayr	1633	@@:
1274	hidnplayr	1634
1514	hidnplayr	1635	;;; 128
1274	hidnplayr	1636
1514	hidnplayr	1637	mov edi, [eax + TCP_SOCKET.SND_NXT]
		1638	add edi, esi ; len
		1639	sub edi, [eax + TCP_SOCKET.SND_UNA]
1533	hidnplayr	1640	add edi, [eax + STREAM_SOCKET.snd + RING_BUFFER.size]
1514	hidnplayr	1641	cmp edi, 0
		1642	jle @f
1274	hidnplayr	1643
1514	hidnplayr	1644	and dl, not (TH_FIN) ; clear the FIN flag
1159	hidnplayr	1645
1514	hidnplayr	1646	@@:
1159	hidnplayr	1647
		1648
1529	hidnplayr	1649	; set ecx to space available in receive buffer
		1650	; From now on, ecx will be the window we advertise to the other end
1159	hidnplayr	1651
1529	hidnplayr	1652	mov ecx, SOCKET_MAXDATA
1533	hidnplayr	1653	sub ecx, [eax + STREAM_SOCKET.rcv + RING_BUFFER.size]
1159	hidnplayr	1654
1514	hidnplayr	1655	;------------------------------
		1656	; Sender silly window avoidance
1159	hidnplayr	1657
1529	hidnplayr	1658	cmp ecx, [eax + TCP_SOCKET.t_maxseg]
1514	hidnplayr	1659	je .send
1274	hidnplayr	1660
1514	hidnplayr	1661	;;; TODO: 144-145
1274	hidnplayr	1662
1514	hidnplayr	1663	test [eax + TCP_SOCKET.t_force], -1
		1664	jnz .send
1274	hidnplayr	1665
1529	hidnplayr	1666	mov ebx, [eax + TCP_SOCKET.max_sndwnd]
		1667	shr ebx, 1
		1668	cmp ecx, ebx
		1669	jge .send
1274	hidnplayr	1670
1529	hidnplayr	1671	mov ebx, [eax + TCP_SOCKET.SND_NXT]
		1672	cmp ebx, [eax + TCP_SOCKET.SND_MAX]
		1673	jl .send
1254	hidnplayr	1674
1514	hidnplayr	1675	;----------------------------------------
		1676	; Check if a window update should be sent
1159	hidnplayr	1677
1529	hidnplayr	1678	test ecx, ecx ; window
		1679	jz .no_window
1159	hidnplayr	1680
1514	hidnplayr	1681	;;; TODO 154-172
1159	hidnplayr	1682
1514	hidnplayr	1683	.no_window:
1159	hidnplayr	1684
1514	hidnplayr	1685	;--------------------------
		1686	; Should a segment be sent?
1159	hidnplayr	1687
1534	hidnplayr	1688	test [eax + TCP_SOCKET.t_flags], TF_ACKNOW
1514	hidnplayr	1689	jnz .send
1159	hidnplayr	1690
1514	hidnplayr	1691	test dl, TH_SYN + TH_RST
		1692	jnz .send
1159	hidnplayr	1693
1534	hidnplayr	1694	mov ebx, [eax + TCP_SOCKET.SND_UP]
		1695	cmp ebx, [eax + TCP_SOCKET.SND_UNA]
1514	hidnplayr	1696	jg .send
1249	hidnplayr	1697
1514	hidnplayr	1698	test dl, TH_FIN
		1699	jz .enter_persist
1318	hidnplayr	1700
1534	hidnplayr	1701	test [eax + TCP_SOCKET.t_flags], TF_SENTFIN
1514	hidnplayr	1702	jnz .send
1254	hidnplayr	1703
1534	hidnplayr	1704	mov ebx, [eax + TCP_SOCKET.SND_NXT]
		1705	cmp ebx, [eax + TCP_SOCKET.SND_UNA]
1514	hidnplayr	1706	je .send
1254	hidnplayr	1707
1514	hidnplayr	1708	;--------------------
		1709	; Enter persist state
1318	hidnplayr	1710
1514	hidnplayr	1711	.enter_persist:
1318	hidnplayr	1712
1519	hidnplayr	1713	DEBUGF 1,"Entering persist state\n"
1318	hidnplayr	1714
1514	hidnplayr	1715	;--------------------------------------
		1716	; No reason to send a segment, just ret
1318	hidnplayr	1717
1514	hidnplayr	1718	DEBUGF 1,"No reason to send a segment\n"
1318	hidnplayr	1719
1514	hidnplayr	1720	ret
1318	hidnplayr	1721
		1722
1514	hidnplayr	1723	;-----------------------------------------------
		1724	;
		1725	; Send a segment
		1726	;
1529	hidnplayr	1727	; eax = socket pointer
1514	hidnplayr	1728	; dl = flags
		1729	;
		1730	;-----------------------------------------------
1318	hidnplayr	1731
1529	hidnplayr	1732	.send:
1318	hidnplayr	1733
1514	hidnplayr	1734	DEBUGF 1,"Preparing to send a segment\n"
1318	hidnplayr	1735
1529	hidnplayr	1736	mov edi, TCP_segment.Data ; edi will contain headersize
1318	hidnplayr	1737
1529	hidnplayr	1738	sub esp, 8 ; create some space on stack
		1739	push eax ; save this too..
		1740
1514	hidnplayr	1741	;------------------------------------
		1742	; Send options with first SYN segment
1318	hidnplayr	1743
1514	hidnplayr	1744	test dl, TH_SYN
		1745	jz .no_options
1318	hidnplayr	1746
1529	hidnplayr	1747	push [eax + TCP_SOCKET.ISS]
		1748	pop [eax + TCP_SOCKET.SND_NXT]
1318	hidnplayr	1749
1529	hidnplayr	1750	test [eax + TCP_SOCKET.t_flags], TF_NOOPT
1514	hidnplayr	1751	jnz .no_options
1318	hidnplayr	1752
1529	hidnplayr	1753	mov ecx, 1460
		1754	or ecx, TCP_OPT_MAXSEG shl 24 + 4 shl 16
		1755	bswap ecx
		1756	push ecx
		1757	add di, 4
1514	hidnplayr	1758
1529	hidnplayr	1759	test [eax + TCP_SOCKET.t_flags], TF_REQ_SCALE
1514	hidnplayr	1760	jz .no_syn
		1761
		1762	test dl, TH_ACK
		1763	jnz .scale_opt
		1764
1529	hidnplayr	1765	test [eax + TCP_SOCKET.t_flags], TF_RCVD_SCALE
1514	hidnplayr	1766	jz .no_syn
		1767
		1768	.scale_opt:
1529	hidnplayr	1769	movzx ecx, byte [eax + TCP_SOCKET.request_r_scale]
		1770	or ecx, TCP_OPT_WINDOW shl 24 + 4 shl 16 + TCP_OPT_NOP shl 8
		1771	bswap ecx
		1772	pushd ecx
1514	hidnplayr	1773	add di, 4
1159	hidnplayr	1774
1514	hidnplayr	1775	.no_syn:
1159	hidnplayr	1776
1514	hidnplayr	1777	;------------------------------------
		1778	; Make the timestamp option if needed
1159	hidnplayr	1779
1529	hidnplayr	1780	test [eax + TCP_SOCKET.t_flags], TF_REQ_TSTMP
1514	hidnplayr	1781	jz .no_timestamp
1159	hidnplayr	1782
1514	hidnplayr	1783	test dl, TH_RST
		1784	jnz .no_timestamp
		1785
		1786	test dl, TH_ACK
		1787	jz .timestamp
		1788
1529	hidnplayr	1789	test [eax + TCP_SOCKET.t_flags], TF_RCVD_TSTMP
1514	hidnplayr	1790	jz .no_timestamp
		1791
		1792	.timestamp:
1529	hidnplayr	1793	mov esi, [timer_ticks]
		1794	bswap esi
		1795	push esi
1514	hidnplayr	1796	pushw 0
1529	hidnplayr	1797	pushd TCP_OPT_TIMESTAMP + 10 shl 8 + TCP_OPT_NOP shl 16 + TCP_OPT_NOP shl 24
1514	hidnplayr	1798	add di, 10
		1799
		1800	.no_timestamp:
		1801	;; TODO: check if we dont exceed the max segment size
		1802
		1803	.no_options:
1529	hidnplayr	1804	; eax = socket ptr
		1805	; edx = flags
		1806	; ecx = data size
		1807	; edi = header size
		1808	; esi = snd ring buff ptr
1514	hidnplayr	1809
1533	hidnplayr	1810	mov ecx, [eax + STREAM_SOCKET.snd + RING_BUFFER.size]
		1811	cmp ecx, [eax + TCP_SOCKET.t_maxseg] ;;; right?
		1812	jle @f
		1813	mov ecx, [eax + TCP_SOCKET.t_maxseg]
		1814	@@:
1514	hidnplayr	1815	add ecx, edi ; total TCP segment size
		1816
1529	hidnplayr	1817	; Start by pushing all TCP header values in reverse order on stack
		1818	; (essentially, creating the tcp header!)
1514	hidnplayr	1819
1529	hidnplayr	1820	pushw 0 ; .UrgentPointer dw ?
		1821	pushw 0 ; .Checksum dw ?
		1822	pushw 0x00a0 ; .Window dw ? ;;;;;;;
		1823	shl edi, 2 ; .DataOffset db ? only 4 left-most bits
		1824	shl dx, 8
		1825	or dx, di ; .Flags db ?
		1826	pushw dx
		1827	shr edi, 2 ; .DataOffset db ? ;;;;
1514	hidnplayr	1828
1529	hidnplayr	1829	push [eax + TCP_SOCKET.RCV_NXT] ; .AckNumber dd ?
1543	hidnplayr	1830	ntohd [esp]
1159	hidnplayr	1831
1529	hidnplayr	1832	push [eax + TCP_SOCKET.SND_NXT] ; .SequenceNumber dd ?
1543	hidnplayr	1833	ntohd [esp]
1159	hidnplayr	1834
1529	hidnplayr	1835	push [eax + TCP_SOCKET.RemotePort] ; .DestinationPort dw ?
1543	hidnplayr	1836	ntohw [esp]
1249	hidnplayr	1837
1529	hidnplayr	1838	push [eax + TCP_SOCKET.LocalPort] ; .SourcePort dw ?
1543	hidnplayr	1839	ntohw [esp]
1274	hidnplayr	1840
1533	hidnplayr	1841	push edi ; header size
1274	hidnplayr	1842
1529	hidnplayr	1843	; Create the IP packet
		1844	mov ebx, [eax + IP_SOCKET.LocalIP] ; source ip
		1845	mov eax, [eax + IP_SOCKET.RemoteIP] ; dest ip
		1846	mov di, IP_PROTO_TCP shl 8 + 128
		1847	call IPv4_output
		1848	jz .fail
1274	hidnplayr	1849
1529	hidnplayr	1850	;-----------------------------------------
		1851	; Move TCP header from stack to TCP packet
1274	hidnplayr	1852
1533	hidnplayr	1853	push ecx
		1854	mov ecx, [esp+4]
		1855	lea esi, [esp+4+4]
1529	hidnplayr	1856	shr ecx, 2
		1857	rep movsd
1533	hidnplayr	1858	pop ecx ; full TCP packet size
1274	hidnplayr	1859
1533	hidnplayr	1860	pop esi ; headersize
		1861	add esp, esi
1254	hidnplayr	1862
1533	hidnplayr	1863	mov [esp + 4], eax ; packet ptr
1530	hidnplayr	1864	mov [esp + 4+4], edx ; packet size
1254	hidnplayr	1865
1533	hidnplayr	1866	mov edx, edi ; begin of data
		1867	sub edx, esi ; begin of packet (edi = begin of data)
		1868	push ecx
		1869	sub ecx, esi ; data size
1159	hidnplayr	1870
1514	hidnplayr	1871	;--------------
		1872	; Copy the data
1159	hidnplayr	1873
1529	hidnplayr	1874	; eax = ptr to ring struct
		1875	; ecx = buffer size
		1876	; edi = ptr to buffer
1249	hidnplayr	1877
1536	hidnplayr	1878	; test ecx, ecx
1533	hidnplayr	1879	mov eax, [esp+4] ; socket ptr
1536	hidnplayr	1880	add [eax + TCP_SOCKET.SND_NXT], ecx
		1881	add eax, STREAM_SOCKET.snd
1533	hidnplayr	1882	push edx
1529	hidnplayr	1883	call SOCKET_ring_read
1536	hidnplayr	1884	pop esi
		1885	pop ecx
1529	hidnplayr	1886	pop eax
1254	hidnplayr	1887
1533	hidnplayr	1888	test [esi + TCP_segment.Flags], TH_SYN + TH_FIN
		1889	jz @f
		1890	inc [eax + TCP_SOCKET.SND_NXT]
		1891	;;; TODO: update sentfin flag
		1892	@@:
1254	hidnplayr	1893
1533	hidnplayr	1894	mov edx, [eax + TCP_SOCKET.SND_NXT]
		1895	cmp edx, [eax + TCP_SOCKET.SND_MAX]
		1896	jle @f
		1897	mov [eax + TCP_SOCKET.SND_MAX], edx
		1898
		1899	;;;; TODO: time transmission (420)
		1900	@@:
		1901
		1902	;;; TODO: set retransmission timer
		1903
		1904	;--------------------
		1905	; Create the checksum
		1906
1529	hidnplayr	1907	DEBUGF 1,"checksum: ptr=%x size=%u\n", esi, ecx
1159	hidnplayr	1908
1529	hidnplayr	1909	TCP_checksum (eax + IP_SOCKET.LocalIP), (eax + IP_SOCKET.RemoteIP)
		1910	mov [esi+TCP_segment.Checksum], dx
		1911
1514	hidnplayr	1912	;----------------
		1913	; Send the packet
1159	hidnplayr	1914
1529	hidnplayr	1915	DEBUGF 1,"Sending TCP Packet to device %x\n", ebx
		1916	call [ebx + NET_DEVICE.transmit]
		1917	ret
1159	hidnplayr	1918
1514	hidnplayr	1919
1529	hidnplayr	1920	.fail:
		1921	pop ecx
		1922	add esp, ecx
1536	hidnplayr	1923	add esp, 4+8
1529	hidnplayr	1924	DEBUGF 1,"TCP_output: failed\n"
1159	hidnplayr	1925	ret
		1926
1529	hidnplayr	1927
		1928
1514	hidnplayr	1929	;-------------------------
		1930	;
		1931	; TCP_outflags
		1932	;
		1933	; IN: eax = socket ptr
		1934	;
		1935	; OUT: edx = flags
		1936	;
		1937	;-------------------------
1249	hidnplayr	1938	align 4
1514	hidnplayr	1939	TCP_outflags:
1254	hidnplayr	1940
1514	hidnplayr	1941	mov edx, [eax + TCP_SOCKET.t_state]
		1942	movzx edx, byte [edx + .flaglist]
1254	hidnplayr	1943
1514	hidnplayr	1944	DEBUGF 1,"TCP_outflags, socket: %x, flags: %x\n", eax, dl
		1945
1159	hidnplayr	1946	ret
		1947
1514	hidnplayr	1948	.flaglist:
1159	hidnplayr	1949
1514	hidnplayr	1950	db TH_RST + TH_ACK ; TCB_CLOSED
		1951	db 0 ; TCB_LISTEN
		1952	db TH_SYN ; TCB_SYN_SENT
		1953	db TH_SYN + TH_ACK ; TCB_SYN_RECEIVED
		1954	db TH_ACK ; TCB_ESTABLISHED
		1955	db TH_ACK ; TCB_CLOSE_WAIT
		1956	db TH_SYN + TH_ACK ; TCB_FIN_WAIT_1
		1957	db TH_SYN + TH_ACK ; TCB_CLOSING
		1958	db TH_SYN + TH_ACK ; TCB_LAST_ACK
		1959	db TH_ACK ; TCB_FIN_WAIT_2
		1960	db TH_ACK ; TCB_TIMED_WAIT
1249	hidnplayr	1961
1514	hidnplayr	1962
1529	hidnplayr	1963
		1964
1514	hidnplayr	1965	;-------------------------
		1966	;
		1967	; TCP_drop
		1968	;
		1969	; IN: eax = socket ptr
1716	hidnplayr	1970	; ebx = error number
1514	hidnplayr	1971	;
1716	hidnplayr	1972	; OUT: eax = socket ptr
1514	hidnplayr	1973	;
		1974	;-------------------------
1249	hidnplayr	1975	align 4
1514	hidnplayr	1976	TCP_drop:
1254	hidnplayr	1977
1514	hidnplayr	1978	DEBUGF 1,"TCP_drop\n"
1254	hidnplayr	1979
1716	hidnplayr	1980	cmp [eax + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		1981	jl .no_syn_received
1159	hidnplayr	1982
1514	hidnplayr	1983	mov [eax + TCP_SOCKET.t_state], TCB_CLOSED
1159	hidnplayr	1984
1514	hidnplayr	1985	call TCP_output
1254	hidnplayr	1986
1716	hidnplayr	1987	;;; TODO: update stats
1514	hidnplayr	1988
1716	hidnplayr	1989	jmp TCP_close
		1990
		1991	.no_syn_received:
		1992
		1993	;;; TODO: update stats
		1994
		1995	;;; TODO: check if error code is "Connection timed out' and handle accordingly
		1996
		1997	mov [eax + SOCKET.errorcode], ebx
		1998
		1999	jmp TCP_close
		2000
		2001
		2002	;-------------------------
		2003	;
		2004	; TCP_close
		2005	;
		2006	; IN: eax = socket ptr
		2007	; OUT: eax = socket ptr
		2008	;
		2009	;-------------------------
		2010	align 4
		2011	TCP_close:
		2012
		2013	;;; TODO: update RTT and mean deviation
		2014	;;; TODO: update slow start threshold
		2015	;;; TODO: release connection resources
		2016
1159	hidnplayr	2017	ret
		2018
		2019
1254	hidnplayr	2020
		2021
1514	hidnplayr	2022	;---------------------------------------
		2023	;
1519	hidnplayr	2024	; The easy way to send an ACK/RST/keepalive segment
1514	hidnplayr	2025	;
1529	hidnplayr	2026	; TCP_respond_socket:
		2027	;
		2028	; IN: ebx = socket ptr
1519	hidnplayr	2029	; cl = flags
1514	hidnplayr	2030	;
1529	hidnplayr	2031	;--------------------------------------
1514	hidnplayr	2032	align 4
1529	hidnplayr	2033	TCP_respond_socket:
1254	hidnplayr	2034
1529	hidnplayr	2035	DEBUGF 1,"TCP_respond_socket\n"
1159	hidnplayr	2036
1519	hidnplayr	2037	;---------------------
		2038	; Create the IP packet
		2039
1529	hidnplayr	2040	push cx ebx
		2041	mov eax, [ebx + IP_SOCKET.RemoteIP]
		2042	mov ebx, [ebx + IP_SOCKET.LocalIP]
1519	hidnplayr	2043	mov ecx, TCP_segment.Data
1529	hidnplayr	2044	mov di , IP_PROTO_TCP shl 8 + 128
		2045	call IPv4_output
1519	hidnplayr	2046	test edi, edi
		2047	jz .error
1529	hidnplayr	2048	pop esi cx
		2049	push edx eax
1519	hidnplayr	2050
1529	hidnplayr	2051	;-----------------------------------------------
		2052	; Fill in the TCP header by using the socket ptr
1519	hidnplayr	2053
1529	hidnplayr	2054	mov ax, [esi + TCP_SOCKET.LocalPort]
		2055	rol ax, 8
		2056	stosw
		2057	mov ax, [esi + TCP_SOCKET.RemotePort]
		2058	rol ax, 8
		2059	stosw
		2060	mov eax, [esi + TCP_SOCKET.SND_NXT]
		2061	bswap eax
		2062	stosd
		2063	mov eax, [esi + TCP_SOCKET.RCV_NXT]
		2064	bswap eax
		2065	stosd
		2066	mov al, 0x50 ; Dataoffset: 20 bytes
		2067	stosb
		2068	mov al, cl
		2069	stosb
		2070	mov ax, [esi + TCP_SOCKET.RCV_WND]
		2071	rol ax, 8
		2072	stosw ; window
		2073	xor eax, eax
		2074	stosd ; checksum + urgentpointer
1519	hidnplayr	2075
		2076	;---------------------
		2077	; Fill in the checksum
		2078
		2079	.checksum:
1529	hidnplayr	2080	sub edi, TCP_segment.Data
		2081	mov ecx, TCP_segment.Data
		2082	xchg esi, edi
		2083	TCP_checksum (edi + IP_SOCKET.LocalIP), (esi + IP_SOCKET.RemoteIP)
		2084	mov [esi+TCP_segment.Checksum], dx
1519	hidnplayr	2085
		2086	;--------------------
		2087	; And send the segment
		2088
		2089	call [ebx + NET_DEVICE.transmit]
1159	hidnplayr	2090	ret
		2091
1519	hidnplayr	2092	.error:
1529	hidnplayr	2093	DEBUGF 1,"TCP_respond failed\n"
		2094	add esp, 2+4
1159	hidnplayr	2095
1519	hidnplayr	2096	ret
1514	hidnplayr	2097
1529	hidnplayr	2098
		2099
		2100	;-------------------------
		2101	; TCP_respond.segment:
		2102	;
		2103	; IN: edx = segment ptr (a previously received segment)
		2104	; cl = flags
		2105
		2106	align 4
		2107	TCP_respond_segment:
		2108
		2109	DEBUGF 1,"TCP_respond_segment\n"
		2110
		2111	;---------------------
		2112	; Create the IP packet
		2113
		2114	push cx edx
		2115	mov ebx, [edx - 20 + IPv4_Packet.SourceAddress] ;;;; and what if ip packet had options?!
		2116	mov eax, [edx - 20 + IPv4_Packet.DestinationAddress] ;;;
		2117	mov ecx, TCP_segment.Data
		2118	mov di , IP_PROTO_TCP shl 8 + 128
		2119	call IPv4_output
		2120	jz .error
1533	hidnplayr	2121	pop esi cx
1529	hidnplayr	2122
		2123	push edx eax
		2124
1519	hidnplayr	2125	;---------------------------------------------------
		2126	; Fill in the TCP header by using a received segment
		2127
		2128	mov ax, [esi + TCP_segment.DestinationPort]
		2129	rol ax, 8
		2130	stosw
		2131	mov ax, [esi + TCP_segment.SourcePort]
		2132	rol ax, 8
		2133	stosw
		2134	mov eax, [esi + TCP_segment.AckNumber]
		2135	bswap eax
		2136	stosd
		2137	xor eax, eax
		2138	stosd
		2139	mov al, 0x50 ; Dataoffset: 20 bytes
		2140	stosb
		2141	mov al, cl
		2142	stosb
		2143	mov ax, 1280
		2144	rol ax, 8
		2145	stosw ; window
		2146	xor eax, eax
		2147	stosd ; checksum + urgentpointer
		2148
1529	hidnplayr	2149	;---------------------
		2150	; Fill in the checksum
1519	hidnplayr	2151
1529	hidnplayr	2152	.checksum:
		2153	lea esi, [edi - TCP_segment.Data]
		2154	mov ecx, TCP_segment.Data
		2155	TCP_checksum (esi - 20 + IPv4_Packet.DestinationAddress), (esi - 20 + IPv4_Packet.DestinationAddress)
		2156	mov [esi+TCP_segment.Checksum], dx
1519	hidnplayr	2157
1529	hidnplayr	2158	;--------------------
		2159	; And send the segment
1519	hidnplayr	2160
1529	hidnplayr	2161	call [ebx + NET_DEVICE.transmit]
		2162	ret
1519	hidnplayr	2163
1529	hidnplayr	2164	.error:
		2165	DEBUGF 1,"TCP_respond failed\n"
		2166	add esp, 2+4
1519	hidnplayr	2167
		2168	ret
		2169
		2170
		2171
1254	hidnplayr	2172
		2173	;---------------------------------------------------------------------------
		2174	;
		2175	; TCP_API
		2176	;
		2177	; This function is called by system function 75
		2178	;
		2179	; IN: subfunction number in bl
		2180	; device number in bh
		2181	; ecx, edx, .. depends on subfunction
		2182	;
		2183	; OUT:
		2184	;
		2185	;---------------------------------------------------------------------------
		2186	align 4
		2187	TCP_API:
		2188
		2189	movzx eax, bh
		2190	shl eax, 2
		2191
		2192	test bl, bl
		2193	jz .packets_tx ; 0
		2194	dec bl
		2195	jz .packets_rx ; 1
		2196
		2197	.error:
		2198	mov eax, -1
		2199	ret
		2200
		2201	.packets_tx:
1514	hidnplayr	2202	add eax, TCP_segments_tx
1254	hidnplayr	2203	mov eax, [eax]
		2204	ret
		2205
		2206	.packets_rx:
1514	hidnplayr	2207	add eax, TCP_segments_rx
1254	hidnplayr	2208	mov eax, [eax]
		2209	ret

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