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: 1542 $
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
		359	ntohld [edx + TCP_segment.SequenceNumber]
		360	ntohld [edx + TCP_segment.AckNumber]
		361
		362	ntohlw [edx + TCP_segment.Window]
		363	ntohlw [edx + TCP_segment.UrgentPointer]
1529	hidnplayr	364	ntohlw [edx + TCP_segment.SourcePort]
		365	ntohlw [edx + TCP_segment.DestinationPort]
1514	hidnplayr	366
		367	;------------------------------------------------------------
		368	; Next thing to do is find the TCB (thus, the socket pointer)
		369
1274	hidnplayr	370	; IP Packet TCP Destination Port = local Port
1514	hidnplayr	371	; (IP Packet SenderAddress = Remote IP) OR (Remote IP = 0)
1318	hidnplayr	372	; (IP Packet TCP Source Port = remote Port) OR (remote Port = 0)
1159	hidnplayr	373
		374	mov ebx, net_sockets
		375
1249	hidnplayr	376	.socket_loop:
1514	hidnplayr	377	mov ebx, [ebx + SOCKET.NextPtr]
1159	hidnplayr	378	or ebx, ebx
1514	hidnplayr	379	jz .drop_with_reset
1159	hidnplayr	380
1542	hidnplayr	381	cmp [ebx + SOCKET.Protocol], IP_PROTO_TCP ;;; We should also check if family is AF_INET
1249	hidnplayr	382	jne .socket_loop
1159	hidnplayr	383
1514	hidnplayr	384	mov ax, [edx + TCP_segment.DestinationPort]
		385	cmp [ebx + TCP_SOCKET.LocalPort], ax
		386	jne .socket_loop
		387
		388	mov eax, [ebx + IP_SOCKET.RemoteIP]
1529	hidnplayr	389	cmp eax, edi ; sender IP
1249	hidnplayr	390	je @f
		391	test eax, eax
1514	hidnplayr	392	jnz .socket_loop
1249	hidnplayr	393	@@:
1159	hidnplayr	394
1514	hidnplayr	395	mov ax, [ebx + TCP_SOCKET.RemotePort]
		396	cmp [edx + TCP_segment.SourcePort] , ax
1274	hidnplayr	397	je .found_socket
1249	hidnplayr	398	test ax, ax
1254	hidnplayr	399	jnz .socket_loop
1274	hidnplayr	400	.found_socket:
1529	hidnplayr	401	DEBUGF 1,"Socket ptr: %x\n", ebx
1254	hidnplayr	402
1514	hidnplayr	403	; ebx now contains the pointer to the socket
1257	hidnplayr	404
1514	hidnplayr	405	;----------------------------
		406	; Check if socket isnt closed
		407
1529	hidnplayr	408	cmp [ebx + TCP_SOCKET.t_state], TCB_CLOSED
1514	hidnplayr	409	je .drop
		410
		411	;----------------
		412	; Lock the socket
		413
1529	hidnplayr	414	;; add ebx, SOCKET.lock ; TODO: figure out if we should lock now already
		415	;; call wait_mutex
		416	;; sub ebx, SOCKET.lock
1159	hidnplayr	417
1529	hidnplayr	418	DEBUGF 1,"Socket locked\n"
1159	hidnplayr	419
1529	hidnplayr	420	;----------------------------------------------------------------------------------------
		421	; unscale the window into a 32 bit value (notice that SND_SCALE must be initialised to 0)
		422
1514	hidnplayr	423	movzx eax, [edx + TCP_segment.Window]
1534	hidnplayr	424	push ecx
1529	hidnplayr	425	mov cl, [ebx + TCP_SOCKET.SND_SCALE]
1514	hidnplayr	426	shl eax, cl
1534	hidnplayr	427	pop ecx
1514	hidnplayr	428
1529	hidnplayr	429	;;;; do something with eax
1514	hidnplayr	430
		431	;-----------------------------------
		432	; Is this socket a listening socket?
		433
1533	hidnplayr	434	test [ebx + SOCKET.options], SO_ACCEPTCON
1529	hidnplayr	435	; jnz .listening_socket ;;;;; TODO
1514	hidnplayr	436
1529	hidnplayr	437	;-------------------------------------
		438	; Reset idle timer and keepalive timer
1514	hidnplayr	439
1529	hidnplayr	440	mov [ebx + TCP_SOCKET.t_idle], 0
		441	mov [ebx + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval
1514	hidnplayr	442
1529	hidnplayr	443	;--------------------
		444	; Process TCP options
1514	hidnplayr	445
1529	hidnplayr	446	cmp esi, 20 ; esi is headersize
		447	je .no_options
1514	hidnplayr	448
1529	hidnplayr	449	DEBUGF 1,"Segment has options\n"
1514	hidnplayr	450
1530	hidnplayr	451	cmp [ebx + TCP_SOCKET.t_state], TCB_LISTEN ; no options when in listen state
1529	hidnplayr	452	jz .no_options
1514	hidnplayr	453
1529	hidnplayr	454	lea edi, [edx + TCP_segment.Data]
		455	lea eax, [edx + esi]
1514	hidnplayr	456
1529	hidnplayr	457	.opt_loop:
		458	cmp edi, eax
		459	jge .no_options
1514	hidnplayr	460
1529	hidnplayr	461	cmp byte [edi], TCP_OPT_EOL ; end of option list?
		462	jz .no_options
1514	hidnplayr	463
1529	hidnplayr	464	cmp byte [edi], TCP_OPT_NOP ; nop ?
		465	jz .opt_nop
1514	hidnplayr	466
1529	hidnplayr	467	cmp byte [edi], TCP_OPT_MAXSEG
		468	je .opt_maxseg
1514	hidnplayr	469
1529	hidnplayr	470	cmp byte [edi], TCP_OPT_WINDOW
		471	je .opt_window
1514	hidnplayr	472
1529	hidnplayr	473	cmp byte [edi], TCP_OPT_TIMESTAMP
		474	je .opt_timestamp
1514	hidnplayr	475
1529	hidnplayr	476	jmp .no_options ; If we reach here, some unknown options were received, skip them all!
1514	hidnplayr	477
1529	hidnplayr	478	.opt_nop:
		479	inc edi
		480	jmp .opt_loop
1514	hidnplayr	481
1529	hidnplayr	482	.opt_maxseg:
		483	cmp byte [edi+1], 4
		484	jne .no_options ; error occured, ignore all options!
1514	hidnplayr	485
1529	hidnplayr	486	test [edx + TCP_segment.Flags], TH_SYN
		487	jz @f
		488
1530	hidnplayr	489	movzx eax, word[edi+2]
		490	rol ax, 8
1533	hidnplayr	491	DEBUGF 1,"Maxseg: %u\n", ax
1529	hidnplayr	492
1530	hidnplayr	493	mov [ebx + TCP_SOCKET.t_maxseg], eax
		494
1529	hidnplayr	495	@@:
		496	add edi, 4
		497	jmp .opt_loop
		498
		499
		500	.opt_window:
		501	cmp byte [edi+1], 3
		502	jne .no_options
		503
		504	test [edx + TCP_segment.Flags], TH_SYN
		505	jz @f
		506
1533	hidnplayr	507	DEBUGF 1,"Got window option\n"
1529	hidnplayr	508
		509	;;;;;
		510	@@:
		511	add edi, 3
		512	jmp .opt_loop
		513
		514
		515	.opt_timestamp:
		516	cmp byte [edi+1], 10
		517	jne .no_options
		518
1533	hidnplayr	519	DEBUGF 1,"Got timestamp option\n"
1529	hidnplayr	520
		521	;;;;;
		522
		523	add edi, 10
		524	jmp .opt_loop
		525
		526	.no_options:
		527
1514	hidnplayr	528	;-----------------------------------------------------------------------
		529	; Time to do some header prediction (Original Principle by Van Jacobson)
		530
		531	; There are two common cases for an uni-directional data transfer.
		532	;
		533	; General rule: the packets has no control flags, is in-sequence,
		534	; window width didnt change and we're not retransmitting.
		535	;
		536	; Second rules:
		537	; - If the length is 0 and the ACK moved forward, we're the sender side of the transfer.
		538	; In this case we'll free the ACK'ed data and notify higher levels that we have free space in buffer
		539	;
		540	; - If the length is not 0 and the ACK didn't move, we're the receiver side of the transfer.
		541	; If the packets are in order (data queue is empty), add the data to the socket buffer and request a delayed ACK
		542
1529	hidnplayr	543	cmp [ebx + TCP_SOCKET.t_state], TCB_ESTABLISHED
1514	hidnplayr	544	jnz .not_uni_xfer
		545
1529	hidnplayr	546	test [edx + TCP_segment.Flags], TH_SYN + TH_FIN + TH_RST + TH_URG
1514	hidnplayr	547	jnz .not_uni_xfer
		548
1529	hidnplayr	549	test [edx + TCP_segment.Flags], TH_ACK
1514	hidnplayr	550	jz .not_uni_xfer
		551
		552	mov eax, [edx + TCP_segment.SequenceNumber]
		553	cmp eax, [ebx + TCP_SOCKET.RCV_NXT]
		554	jne .not_uni_xfer
		555
1536	hidnplayr	556	movzx eax, [edx + TCP_segment.Window] ;;;;; (should use pre-calculated value instead: todo: figure out where to store it)
		557	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		558	jne .not_uni_xfer
1514	hidnplayr	559
		560	mov eax, [ebx + TCP_SOCKET.SND_NXT]
		561	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		562	jne .not_uni_xfer
		563
		564	;---------------------------------------
		565	; check if we are sender in the uni-xfer
		566
		567	; If the following 4 conditions are all true, this segment is a pure ACK.
		568	;
1529	hidnplayr	569	; - The segment contains no data.
		570	test ecx, ecx
1514	hidnplayr	571	jnz .not_sender
1274	hidnplayr	572
1529	hidnplayr	573	; - The congestion window is greater than or equal to the current send window.
1514	hidnplayr	574	; This test is true only if the window is fully open, that is, the connection is not in the middle of slow start or congestion avoidance.
		575	mov eax, [ebx + TCP_SOCKET.SND_CWND]
		576	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		577	jl .not_uni_xfer
1318	hidnplayr	578
1529	hidnplayr	579	; - The acknowledgment field in the segment is less than or equal to the maximum sequence number sent.
1534	hidnplayr	580	mov eax, [edx + TCP_segment.AckNumber]
		581	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
1529	hidnplayr	582	jg .not_uni_xfer
		583
		584	; - The acknowledgment field in the segment is greater than the largest unacknowledged sequence number.
1534	hidnplayr	585	sub eax, [ebx + TCP_SOCKET.SND_UNA]
1529	hidnplayr	586	jle .not_uni_xfer
		587
1514	hidnplayr	588	DEBUGF 1,"Header prediction: we are sender\n"
1274	hidnplayr	589
1514	hidnplayr	590	;---------------------------------
		591	; Packet is a pure ACK, process it
1274	hidnplayr	592
1514	hidnplayr	593	; Update RTT estimators
1159	hidnplayr	594
1514	hidnplayr	595	; Delete acknowledged bytes from send buffer
1536	hidnplayr	596	mov ecx, eax
1533	hidnplayr	597	lea eax, [ebx + STREAM_SOCKET.snd]
1529	hidnplayr	598	call SOCKET_ring_free
		599
1536	hidnplayr	600	; update window pointers
		601	mov eax, [edx + TCP_segment.AckNumber]
		602	dec eax
		603	mov [ebx + TCP_SOCKET.SND_WL1], eax
		604
1514	hidnplayr	605	; Stop retransmit timer
1519	hidnplayr	606	mov [ebx + TCP_SOCKET.timer_ack], 0
1159	hidnplayr	607
1514	hidnplayr	608	; Awaken waiting processes
1519	hidnplayr	609	mov eax, ebx
		610	call SOCKET_notify_owner
1318	hidnplayr	611
1536	hidnplayr	612	;; Generate more output
		613	;; mov eax, ebx
		614	;; call TCP_output
		615	;;
		616	;; jmp .drop
		617	jmp .step6
1254	hidnplayr	618
1514	hidnplayr	619	;-------------------------------------------------
		620	; maybe we are the receiver in the uni-xfer then..
		621
		622	.not_sender:
1529	hidnplayr	623	; - The amount of data in the segment is greater than 0 (data count is in ecx)
1514	hidnplayr	624
1529	hidnplayr	625	; - The acknowledgment field equals the largest unacknowledged sequence number. This means no data is acknowledged by this segment.
1514	hidnplayr	626	mov eax, [edx + TCP_segment.AckNumber]
		627	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
		628	jne .not_uni_xfer
		629
1529	hidnplayr	630	; - The reassembly list of out-of-order segments for the connection is empty (seg_next equals tp). ;;;;;;;
1514	hidnplayr	631
		632	jnz .not_uni_xfer
		633
		634	;-------------------------------------
		635	; Complete processing of received data
		636
		637	DEBUGF 1,"header prediction: we are receiver\nreceiving %u bytes of data\n", ecx
		638
1529	hidnplayr	639	add esi, edx
1533	hidnplayr	640	lea eax, [ebx + STREAM_SOCKET.rcv]
		641	call SOCKET_ring_write ; Add the data to the socket buffer
1514	hidnplayr	642
1533	hidnplayr	643	mov eax, ebx
		644	call SOCKET_notify_owner
		645
1529	hidnplayr	646	add [ebx + TCP_SOCKET.RCV_NXT], ecx ; Update sequence number with number of bytes we have copied
		647	or [ebx + TCP_SOCKET.t_flags], TF_DELACK ; Set delayed ack flag
1514	hidnplayr	648
		649	jmp .drop
		650
		651	;----------------------------------------------------
1529	hidnplayr	652	; Header prediction failed, doing it the slow way.. ;;;;; current implementation of header prediction destroys some regs (ecx) !!
1514	hidnplayr	653
		654	.not_uni_xfer:
		655
1533	hidnplayr	656	DEBUGF 1,"Header prediction failed\n" ; time to do it the "slow" way :)
1514	hidnplayr	657
		658	;------------------------------
		659	; Calculate receive window size
		660
		661	;;;;
		662
1529	hidnplayr	663	cmp [ebx + TCP_SOCKET.t_state], TCB_LISTEN
1514	hidnplayr	664	je .LISTEN
		665
1529	hidnplayr	666	cmp [ebx + TCP_SOCKET.t_state], TCB_SYN_SENT
1514	hidnplayr	667	je .SYN_SENT
		668
		669	;--------------------------------------------
		670	; Protection Against Wrapped Sequence Numbers
		671
1533	hidnplayr	672	; First, check if timestamp is present
1514	hidnplayr	673
		674	;;;; TODO
		675
		676	; Then, check if at least some bytes of data are within window
		677
		678	;;;; TODO
		679
		680	jmp .trim_then_step6
		681
1529	hidnplayr	682	;-------------
		683	; Passive Open
		684
1249	hidnplayr	685	align 4
1514	hidnplayr	686	.LISTEN:
1196	hidnplayr	687
1514	hidnplayr	688	DEBUGF 1,"TCP state: listen\n"
1159	hidnplayr	689
1514	hidnplayr	690	test [edx + TCP_segment.Flags], TH_RST
		691	jnz .drop
1159	hidnplayr	692
1514	hidnplayr	693	test [edx + TCP_segment.Flags], TH_ACK
		694	jnz .drop_with_reset
1159	hidnplayr	695
1514	hidnplayr	696	test [edx + TCP_segment.Flags], TH_SYN
		697	jz .drop
1159	hidnplayr	698
1533	hidnplayr	699	cmp esi, 0xffffff ; destination ip = 255.255.255.255 ?
		700	jz .drop
		701
1514	hidnplayr	702	; TODO: check if it's a broadcast or multicast, and drop if so
1159	hidnplayr	703
1529	hidnplayr	704	call SOCKET_fork
		705	jz .drop ; if we could not open a new connection, drop segment (;;;; should we send RST too?)
1514	hidnplayr	706
1529	hidnplayr	707	;-----------------------
		708	; Fill in some variables
1514	hidnplayr	709
1529	hidnplayr	710	add [TCP_sequence_num], 64000
1514	hidnplayr	711
1529	hidnplayr	712	push [edx + TCP_segment.SourcePort]
		713	pop [eax + TCP_SOCKET.RemotePort]
1514	hidnplayr	714
1529	hidnplayr	715	push [edx + TCP_segment.SequenceNumber]
		716	pop [eax + TCP_SOCKET.IRS]
1159	hidnplayr	717
1529	hidnplayr	718	push [eax + TCP_SOCKET.ISS]
		719	pop [eax + TCP_SOCKET.SND_NXT]
1159	hidnplayr	720
1529	hidnplayr	721	mov [eax + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		722	mov [eax + TCP_SOCKET.t_flags], TF_ACKNOW
		723	mov [eax + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval
1159	hidnplayr	724
1529	hidnplayr	725	mov ebx, eax
1514	hidnplayr	726	jmp .trim_then_step6
1159	hidnplayr	727
1254	hidnplayr	728
1529	hidnplayr	729	;------------
		730	; Active Open
1159	hidnplayr	731
1514	hidnplayr	732	align 4
		733	.SYN_SENT:
1281	hidnplayr	734
1514	hidnplayr	735	DEBUGF 1,"TCP state: syn_sent\n"
1159	hidnplayr	736
1514	hidnplayr	737	test [edx + TCP_segment.Flags], TH_ACK
		738	jz @f
1281	hidnplayr	739
1514	hidnplayr	740	mov eax, [edx + TCP_segment.AckNumber]
		741	cmp eax, [ebx + TCP_SOCKET.ISS]
		742	jle .drop_with_reset
1281	hidnplayr	743
1529	hidnplayr	744	; mov eax, [edx + TCP_segment.AckNumber]
1533	hidnplayr	745	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		746	jg .drop_with_reset
1514	hidnplayr	747	@@:
1281	hidnplayr	748
1514	hidnplayr	749	test [edx + TCP_segment.Flags], TH_RST
		750	jz @f
1281	hidnplayr	751
1514	hidnplayr	752	test [edx + TCP_segment.Flags], TH_ACK
		753	jz .drop
1281	hidnplayr	754
1514	hidnplayr	755	;tp = tcp_drop(tp, ECONNREFUSED)
1159	hidnplayr	756
1514	hidnplayr	757	jmp .drop
		758	@@:
1159	hidnplayr	759
1514	hidnplayr	760	test [edx + TCP_segment.Flags], TH_SYN
		761	jz .drop
1318	hidnplayr	762
1529	hidnplayr	763	; at this point, segment seems to be valid
		764
1514	hidnplayr	765	test [edx + TCP_segment.Flags], TH_ACK
1529	hidnplayr	766	jz .no_syn_ack
1514	hidnplayr	767
1529	hidnplayr	768	; now, process received SYN in response to an active open
		769
1514	hidnplayr	770	mov eax, [edx + TCP_segment.AckNumber]
		771	mov [ebx + TCP_SOCKET.SND_UNA], eax
		772	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		773	jle @f
		774	mov [ebx + TCP_SOCKET.SND_NXT], eax
1529	hidnplayr	775	@@:
1514	hidnplayr	776
1529	hidnplayr	777	.no_syn_ack:
1514	hidnplayr	778
1529	hidnplayr	779	mov [ebx + TCP_SOCKET.timer_retransmission], 0 ; disable retransmission
1514	hidnplayr	780
1529	hidnplayr	781	push [edx + TCP_segment.SequenceNumber]
		782	pop [ebx + TCP_SOCKET.IRS]
		783
1533	hidnplayr	784	TCP_rcvseqinit ebx
1529	hidnplayr	785
		786	mov [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
		787
		788	mov eax, [ebx + TCP_SOCKET.SND_UNA]
		789	cmp eax, [ebx + TCP_SOCKET.ISS]
		790	jle .simultaneous_open
		791
		792	test [edx + TCP_segment.Flags], TH_ACK
		793	jz .simultaneous_open
		794
		795	DEBUGF 1,"TCP: active open\n"
		796
		797	; TODO: update stats
1533	hidnplayr	798	; TODO: set general socket state to connected
1514	hidnplayr	799
		800	mov [ebx + TCP_SOCKET.t_state], TCB_ESTABLISHED
		801
		802	; TODO: check if we should scale the connection (567-572)
		803	; TODO: update RTT estimators
		804
1529	hidnplayr	805	jmp .trimthenstep6
1514	hidnplayr	806
1529	hidnplayr	807	.simultaneous_open:
1514	hidnplayr	808
1529	hidnplayr	809	DEBUGF 1,"TCP: simultaneous open\n"
1514	hidnplayr	810	; We have received a syn but no ACK, so we are having a simultaneous open..
		811	mov [ebx + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		812
		813	;-------------------------------------
		814	; Common processing for receipt of SYN
		815
		816	.trimthenstep6:
		817
		818	inc [edx + TCP_segment.SequenceNumber]
		819
		820	cmp cx, [ebx + TCP_SOCKET.RCV_WND]
		821	jle @f
		822
		823	movzx eax, cx
		824	sub ax, [ebx + TCP_SOCKET.RCV_WND]
		825	; TODO: 592
		826	mov cx, [ebx + TCP_SOCKET.RCV_WND]
		827	; TODO...
		828	@@:
		829	;;;;;
1529	hidnplayr	830	jmp .step6
1514	hidnplayr	831
		832
		833
		834
		835
1529	hidnplayr	836	.trim_then_step6:
1159	hidnplayr	837
1514	hidnplayr	838	;----------------------------
		839	; trim any data not in window
1159	hidnplayr	840
1533	hidnplayr	841	DEBUGF 1,"Trimming window\n"
		842
1514	hidnplayr	843	mov eax, [ebx + TCP_SOCKET.RCV_NXT]
		844	sub eax, [edx + TCP_segment.SequenceNumber]
1318	hidnplayr	845
1514	hidnplayr	846	test eax, eax
1533	hidnplayr	847	jz .no_duplicate
1274	hidnplayr	848
1514	hidnplayr	849	test [edx + TCP_segment.Flags], TH_SYN
		850	jz .no_drop
		851
		852	and [edx + TCP_segment.Flags], not (TH_SYN)
		853	inc [edx + TCP_segment.SequenceNumber]
		854
		855	cmp [edx + TCP_segment.UrgentPointer], 1
		856	jl @f
		857
		858	dec [edx + TCP_segment.UrgentPointer]
		859
		860	jmp .no_drop
		861	@@:
		862
		863	and [edx + TCP_segment.Flags], not (TH_URG)
		864	dec eax
1533	hidnplayr	865	jz .no_duplicate
1514	hidnplayr	866	.no_drop:
		867
1533	hidnplayr	868	DEBUGF 1,"Going to drop %u out of %u bytes\n", eax, ecx
1529	hidnplayr	869
1514	hidnplayr	870	; eax holds number of bytes to drop
		871
		872	;----------------------------------
		873	; Check for entire duplicate packet
		874
		875	cmp eax, ecx
		876	jge .duplicate
		877
		878	;;; TODO: figure 28.30
		879
		880	;------------------------
		881	; Check for duplicate FIN
		882
		883	test [edx + TCP_segment.Flags], TH_FIN
		884	jz @f
		885	inc ecx
		886	cmp eax, ecx
		887	dec ecx
		888	jne @f
		889
		890	mov eax, ecx
		891	and [edx + TCP_segment.Flags], not TH_FIN
1529	hidnplayr	892	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1514	hidnplayr	893	jmp .no_duplicate
		894	@@:
		895
		896	; Handle the case when a bound socket connects to itself
		897	; Allow packets with a SYN and an ACKto continue with the processing
		898
		899	;-------------------------------------
		900	; Generate duplicate ACK if nescessary
		901
		902	; This code also handles simultaneous half-open or self-connects
		903
		904	test eax, eax
		905	jnz .drop_after_ack
		906
		907	cmp [edx + TCP_segment.Flags], TH_ACK
		908	jz .drop_after_ack
		909
		910	.duplicate:
		911
1533	hidnplayr	912	DEBUGF 1,"Duplicate received\n"
1529	hidnplayr	913
1514	hidnplayr	914	;----------------------------------------
		915	; Update statistics for duplicate packets
		916
		917	;;; TODO
		918
1529	hidnplayr	919	jmp .drop ;;; DROP the packet ??
1514	hidnplayr	920
		921	.no_duplicate:
		922
		923	;-----------------------------------------------
		924	; Remove duplicate data and update urgent offset
		925
		926	add [edx + TCP_segment.SequenceNumber], eax
		927
		928	;;; TODO
		929
		930	sub [edx + TCP_segment.UrgentPointer], ax
		931	jg @f
		932
		933	and [edx + TCP_segment.Flags], not (TH_URG)
		934	mov [edx + TCP_segment.UrgentPointer], 0
		935	@@:
		936
		937	;--------------------------------------------------
		938	; Handle data that arrives after process terminates
		939
		940	cmp [ebx + SOCKET.PID], 0
1533	hidnplayr	941	jg @f
1514	hidnplayr	942
		943	cmp [ebx + TCP_SOCKET.t_state], TCB_CLOSE_WAIT
		944	jle @f
		945
		946	test ecx, ecx
		947	jz @f
		948
		949	;;; Close the socket
		950	;;; update stats
		951
		952	jmp .drop_with_reset
		953	@@:
		954
		955	;----------------------------------------
		956	; Remove data beyond right edge of window
		957
		958	mov eax, [edx + TCP_segment.SequenceNumber]
		959	add eax, ecx
		960	sub eax, [ebx + TCP_SOCKET.RCV_NXT]
		961	sub ax, [ebx + TCP_SOCKET.RCV_WND]
		962
		963	; eax now holds the number of bytes to drop
		964
		965	jle .no_excess_data
		966
		967	;;; TODO: update stats
		968
		969	cmp eax, ecx
		970	jl .dont_drop_all
		971
		972	;;; TODO 700-736
		973
		974	.dont_drop_all:
		975
		976	.no_excess_data:
		977
		978	;-----------------
		979	; Record timestamp
		980
		981	;;; TODO 737-746
		982
		983	;------------------
		984	; Process RST flags
		985
		986	test [edx + TCP_segment.Flags], TH_RST
		987	jz .rst_skip
		988
1529	hidnplayr	989	DEBUGF 1,"Got an RST flag"
		990
1514	hidnplayr	991	mov eax, [ebx + TCP_SOCKET.t_state]
		992	shl eax, 2
		993	jmp dword [eax + .rst_sw_list]
		994
		995	.rst_sw_list:
		996	dd .rst_skip ;TCB_CLOSED
		997	dd .rst_skip ;TCB_LISTEN
		998	dd .rst_skip ;TCB_SYN_SENT
		999	dd .econnrefused ;TCB_SYN_RECEIVED
		1000	dd .econnreset ;TCB_ESTABLISHED
		1001	dd .econnreset ;TCB_CLOSE_WAIT
		1002	dd .econnreset ;TCB_FIN_WAIT_1
		1003	dd .rst_close ;TCB_CLOSING
		1004	dd .rst_close ;TCB_LAST_ACK
		1005	dd .econnreset ;TCB_FIN_WAIT_2
		1006	dd .rst_close ;TCB_TIMED_WAIT
		1007
		1008	.econnrefused:
		1009
1529	hidnplayr	1010	DEBUGF 1,"Connection refused"
		1011
1514	hidnplayr	1012	;;; TODO: debug info
		1013
		1014	jmp .close
		1015
		1016	.econnreset:
		1017
1529	hidnplayr	1018	DEBUGF 1,"Connection reset"
		1019
1514	hidnplayr	1020	;;; TODO: debug info
1529	hidnplayr	1021	.close:
1514	hidnplayr	1022
1529	hidnplayr	1023	DEBUGF 1,"Closing connection"
		1024
1514	hidnplayr	1025	;;; update stats
		1026
		1027	.rst_close:
		1028
1534	hidnplayr	1029	DEBUGF 1,"Closing with reset\n"
1529	hidnplayr	1030
1514	hidnplayr	1031	;;; Close the socket
		1032	jmp .drop
		1033
		1034	.rst_skip:
		1035
		1036	;--------------------------------------
		1037	; handle SYN-full and ACK-less segments
		1038
		1039	test [edx + TCP_segment.Flags], TH_SYN
		1040	jz @f
		1041
		1042	;;; tcp_drop ( ECONNRESET)
		1043	jmp .drop_with_reset
		1044
		1045	test [edx + TCP_segment.Flags], TH_ACK
		1046	jz .drop
1534	hidnplayr	1047	@@:
1514	hidnplayr	1048	;----------------
		1049	; Process the ACK
		1050
		1051	cmp [ebx + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		1052	jg .ack_dup
		1053	jl .ack_nodup
		1054
1534	hidnplayr	1055	DEBUGF 1,"TCP state = syn received\n"
1533	hidnplayr	1056
1514	hidnplayr	1057	;;;;;
		1058
1536	hidnplayr	1059	.ack_nodup:
1514	hidnplayr	1060
1536	hidnplayr	1061	DEBUGF 1,"New ACK\n"
1533	hidnplayr	1062
1514	hidnplayr	1063
		1064
1536	hidnplayr	1065	.ack_dup:
1514	hidnplayr	1066
1536	hidnplayr	1067	;;;;
1533	hidnplayr	1068
1514	hidnplayr	1069	;-------------------------------------------------
1519	hidnplayr	1070	; If the congestion window was inflated to account
1514	hidnplayr	1071	; for the other side's cached packets, retrace it
		1072
		1073	;;;; 888 - 902
		1074
		1075
		1076	;------------------------------------------
		1077	; RTT measurements and retransmission timer
		1078
		1079	;;;;; 903 - 926
		1080
1519	hidnplayr	1081	mov [ebx + TCP_SOCKET.timer_retransmission], 0
1514	hidnplayr	1082
1519	hidnplayr	1083	mov eax, [ebx + TCP_SOCKET.SND_MAX]
		1084	cmp eax, [edx + TCP_segment.AckNumber]
		1085	je .all_outstanding
		1086	mov [ebx + TCP_SOCKET.timer_retransmission], 120 ;;;; TODO: correct this value
		1087	.all_outstanding:
		1088
1514	hidnplayr	1089	;-------------------------------------------
		1090	; Open congestion window in response to ACKs
		1091
		1092	;;;;
		1093
		1094
		1095	;------------------------------------------
		1096	; Remove acknowledged data from send buffer
		1097
1536	hidnplayr	1098	pusha
		1099	; Delete acknowledged bytes from send buffer
		1100	mov ecx, [edx + TCP_segment.AckNumber]
		1101	sub ecx, [ebx + TCP_SOCKET.SND_UNA]
1533	hidnplayr	1102	lea eax, [ebx + STREAM_SOCKET.snd]
1536	hidnplayr	1103	call SOCKET_ring_free
		1104	popa
1514	hidnplayr	1105
1536	hidnplayr	1106
		1107	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; code missing (943?)
		1108
1542	hidnplayr	1109
		1110
1536	hidnplayr	1111	mov eax, [edx + TCP_segment.AckNumber]
		1112	mov [ebx + TCP_SOCKET.SND_UNA], eax
		1113
		1114	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		1115	jl @f
		1116	mov [ebx + TCP_SOCKET.SND_NXT], eax
		1117	@@:
		1118
		1119
1514	hidnplayr	1120	;---------------------------------------
		1121	; Wake up process waiting on send buffer
		1122
1529	hidnplayr	1123	mov eax, ebx
		1124	call SOCKET_notify_owner
1514	hidnplayr	1125
		1126	mov eax, [ebx + TCP_SOCKET.t_state]
		1127	shl eax, 2
		1128	jmp dword [eax + .ACK_sw_list]
		1129
		1130	.ACK_sw_list:
		1131	dd .step6 ;TCB_CLOSED
		1132	dd .step6 ;TCB_LISTEN
		1133	dd .step6 ;TCB_SYN_SENT
		1134	dd .step6 ;TCB_SYN_RECEIVED
		1135	dd .step6 ;TCB_ESTABLISHED
		1136	dd .step6 ;TCB_CLOSE_WAIT
		1137	dd ._963 ;TCB_FIN_WAIT_1
		1138	dd ._958 ;TCB_CLOSING
		1139	dd ._999 ;TCB_LAST_ACK
		1140	dd .step6 ;TCB_FIN_WAIT_2
		1141	dd ._1010 ;TCB_TIMED_WAIT
		1142
		1143
1536	hidnplayr	1144	._963:
1514	hidnplayr	1145
		1146
		1147	jmp .step6
		1148
		1149
1536	hidnplayr	1150	._958:
1514	hidnplayr	1151
		1152	jmp .step6
		1153
1536	hidnplayr	1154	._999:
1514	hidnplayr	1155
		1156	jmp .step6
		1157
		1158
1536	hidnplayr	1159	._1010:
1514	hidnplayr	1160
		1161	jmp .step6
		1162
		1163
1536	hidnplayr	1164	.step6:
1514	hidnplayr	1165
		1166	DEBUGF 1,"step 6\n"
		1167
1536	hidnplayr	1168	;----------------------------------------------
		1169	; check if we need to update window information
1514	hidnplayr	1170
		1171	test [edx + TCP_segment.Flags], TH_ACK
		1172	jz .no_window_update
		1173
		1174	mov eax, [ebx + TCP_SOCKET.SND_WL1]
		1175	cmp eax, [edx + TCP_segment.SequenceNumber]
1536	hidnplayr	1176	jl .update_window
		1177	jg @f
1514	hidnplayr	1178
		1179	mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1180	cmp eax, [edx + TCP_segment.AckNumber]
1536	hidnplayr	1181	jl .update_window
		1182	jg .no_window_update
		1183	@@:
1514	hidnplayr	1184
1536	hidnplayr	1185	mov eax, [ebx + TCP_SOCKET.SND_WL2] ;;;;
		1186	cmp eax, [edx + TCP_segment.AckNumber]
		1187	jne .no_window_update
		1188
		1189	movzx eax, [edx + TCP_segment.Window]
1514	hidnplayr	1190	cmp eax, [ebx + TCP_SOCKET.SND_WND]
1536	hidnplayr	1191	jle .no_window_update
1514	hidnplayr	1192
1536	hidnplayr	1193	.update_window:
1514	hidnplayr	1194
1536	hidnplayr	1195	DEBUGF 1,"Updating window\n"
1514	hidnplayr	1196
1536	hidnplayr	1197	;----------------------------------
		1198	; Keep track of pure window updates
		1199
		1200	; test ecx, ecx
		1201	; jz @f
		1202	;
		1203	; mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1204	; cmp eax, [edx + TCP_segment.AckNumber]
		1205	; jne @f
		1206	;
		1207	; ;; mov eax, tiwin
		1208	; cmp eax, [ebx + TCP_SOCKET.SND_WND]
		1209	; jle @f
		1210	;
		1211	; ;;; update stats
		1212	;
		1213	; @@:
		1214
		1215	movzx eax, [edx + TCP_segment.Window] ;;; FIXME: use pre-calculated value instead!
1514	hidnplayr	1216	cmp eax, [ebx + TCP_SOCKET.max_sndwnd]
		1217	jle @f
		1218	mov [ebx + TCP_SOCKET.max_sndwnd], eax
		1219	@@:
		1220	mov [ebx + TCP_SOCKET.SND_WND], eax
		1221
1536	hidnplayr	1222	push [edx + TCP_segment.SequenceNumber]
		1223	pop [ebx + TCP_SOCKET.SND_WL1]
1514	hidnplayr	1224
1536	hidnplayr	1225	push [edx + TCP_segment.AckNumber]
		1226	pop [ebx + TCP_SOCKET.SND_WL2]
1514	hidnplayr	1227
		1228	;;; needoutput = 1
		1229
		1230	.no_window_update:
		1231
		1232	;-----------------
		1233	; process URG flag
		1234
		1235	test [edx + TCP_segment.Flags], TH_URG
		1236	jz .not_urgent
		1237
		1238	cmp [edx + TCP_segment.UrgentPointer], 0
		1239	jz .not_urgent
		1240
		1241	cmp [ebx + TCP_SOCKET.t_state], TCB_TIMED_WAIT
		1242	je .not_urgent
		1243
		1244	; Ignore bogus urgent offsets
		1245
		1246	;;; 1040-1050
		1247
		1248	movzx eax, [edx + TCP_segment.UrgentPointer]
1533	hidnplayr	1249	add eax, [ebx + STREAM_SOCKET.rcv + RING_BUFFER.size]
1514	hidnplayr	1250	cmp eax, SOCKET_MAXDATA
		1251	jle .not_urgent
		1252
		1253	mov [edx + TCP_segment.UrgentPointer], 0
		1254	and [edx + TCP_segment.Flags], not (TH_URG)
		1255	jmp .do_data
		1256
		1257	.not_urgent:
		1258
		1259	;--------------------------------------
		1260	; processing of received urgent pointer
		1261
1529	hidnplayr	1262	;;; TODO (1051-1093)
1514	hidnplayr	1263
1529	hidnplayr	1264	;--------------------------------
		1265	; process the data in the segment
1514	hidnplayr	1266
1529	hidnplayr	1267	.do_data:
1514	hidnplayr	1268
1534	hidnplayr	1269	DEBUGF 1,"TCP: do data (%u)\n", ecx
1514	hidnplayr	1270
		1271	test [edx + TCP_segment.Flags], TH_FIN
1529	hidnplayr	1272	jnz .process_fin
1514	hidnplayr	1273
1533	hidnplayr	1274	cmp [ebx + TCP_SOCKET.t_state], TCB_FIN_WAIT_1
1514	hidnplayr	1275	jge .dont_do_data
		1276
1533	hidnplayr	1277	test ecx, ecx
		1278	jz .final_processing
		1279
1514	hidnplayr	1280	DEBUGF 1,"Processing data in segment\n"
		1281
1533	hidnplayr	1282	;; TODO: check if data is in sequence !
1514	hidnplayr	1283
1533	hidnplayr	1284	movzx eax, [edx + TCP_segment.DataOffset] ;;; todo: remember this in.. edi ?
		1285	and eax, 0xf0
		1286	shr al, 2
		1287
		1288	lea esi, [edx + eax]
		1289
		1290	or [ebx + TCP_SOCKET.t_flags], TF_DELACK
		1291	add [ebx + TCP_SOCKET.RCV_NXT], ecx ;;; right ?
		1292
		1293	lea eax, [ebx + STREAM_SOCKET.rcv]
		1294	call SOCKET_ring_write
		1295
		1296	mov eax, ebx
		1297	call SOCKET_notify_owner
		1298
1514	hidnplayr	1299	jmp .final_processing
		1300
		1301
		1302	.dont_do_data:
		1303
		1304	;---------------
		1305	; FIN processing
		1306
		1307	.process_fin:
		1308
		1309	DEBUGF 1,"Processing FIN\n"
		1310
		1311	mov eax, [ebx + TCP_SOCKET.t_state]
		1312	shl eax, 2
		1313	jmp dword [eax + .FIN_sw_list]
		1314
		1315	.FIN_sw_list:
		1316	dd .no_fin ;TCB_CLOSED
		1317	dd .no_fin ;TCB_LISTEN
		1318	dd .no_fin ;TCB_SYN_SENT
1533	hidnplayr	1319	dd .fin_syn_est ;TCB_SYN_RECEIVED
		1320	dd .fin_syn_est ;TCB_ESTABLISHED
1514	hidnplayr	1321	dd .no_fin ;TCB_CLOSE_WAIT
1533	hidnplayr	1322	dd .fin_wait1 ;TCB_FIN_WAIT_1
1514	hidnplayr	1323	dd .no_fin ;TCB_CLOSING
		1324	dd .no_fin ;TCB_LAST_ACK
1533	hidnplayr	1325	dd .fin_wait2 ;TCB_FIN_WAIT_2
		1326	dd .fin_timed ;TCB_TIMED_WAIT
1514	hidnplayr	1327
		1328
		1329
1533	hidnplayr	1330	.fin_syn_est:
1514	hidnplayr	1331
1533	hidnplayr	1332	jmp .final_processing
1514	hidnplayr	1333
1533	hidnplayr	1334	.fin_wait1:
1514	hidnplayr	1335
1533	hidnplayr	1336	jmp .final_processing
1514	hidnplayr	1337
1533	hidnplayr	1338	.fin_wait2:
1514	hidnplayr	1339
1533	hidnplayr	1340	jmp .final_processing
		1341
		1342	.fin_timed:
		1343
		1344	jmp .final_processing
		1345
1514	hidnplayr	1346	.no_fin:
		1347
		1348	;-----------------
		1349	; Final processing
		1350
		1351	.final_processing:
		1352
		1353	DEBUGF 1,"Final processing\n"
		1354
1533	hidnplayr	1355	mov [ebx + SOCKET.lock], 0
		1356
1514	hidnplayr	1357	;;; if debug enabled, output packet
		1358
		1359	;test ;;;needoutput = 1
		1360	;jnz .outputnow
		1361
		1362	test [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1529	hidnplayr	1363	jnz .ack_now
1514	hidnplayr	1364
1529	hidnplayr	1365	call kernel_free
		1366	add esp, 4
		1367	ret
		1368
		1369	.ack_now:
		1370
		1371	DEBUGF 1,"ACK now!\n"
		1372
		1373	push ebx
		1374	mov eax, ebx
1514	hidnplayr	1375	call TCP_output
1529	hidnplayr	1376	pop ebx
1514	hidnplayr	1377
1274	hidnplayr	1378	call kernel_free
1529	hidnplayr	1379	add esp, 4
		1380	ret
1274	hidnplayr	1381
1514	hidnplayr	1382	;------------------------------------------
		1383	; Generate an ACK, droping incoming segment
1274	hidnplayr	1384
1514	hidnplayr	1385	align 4
		1386	.drop_after_ack:
1274	hidnplayr	1387
1514	hidnplayr	1388	DEBUGF 1,"Drop after ACK\n"
1274	hidnplayr	1389
1514	hidnplayr	1390	test [edx + TCP_segment.Flags], TH_RST
		1391	jnz .drop
1274	hidnplayr	1392
1514	hidnplayr	1393	and [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1274	hidnplayr	1394
1529	hidnplayr	1395	push ebx
		1396	mov eax, ebx
1514	hidnplayr	1397	call TCP_output
1529	hidnplayr	1398	pop ebx
1318	hidnplayr	1399
1514	hidnplayr	1400	call kernel_free
1529	hidnplayr	1401	add esp, 4
		1402	ret
1274	hidnplayr	1403
1514	hidnplayr	1404
		1405	;-------------------------------------------
		1406	; Generate an RST, dropping incoming segment
		1407
		1408	align 4
		1409	.drop_with_reset:
		1410
		1411	DEBUGF 1,"Drop with reset\n"
		1412
		1413	test [edx + TCP_segment.Flags], TH_RST
		1414	jnz .drop
		1415
		1416	;;; if its a multicast/broadcast, also drop
		1417
		1418	test [edx + TCP_segment.Flags], TH_ACK
		1419	jnz .respond_ack
		1420
		1421	test [edx + TCP_segment.Flags], TH_SYN
		1422	jnz .respond_syn
		1423
		1424	call kernel_free
1529	hidnplayr	1425	add esp, 4
		1426	ret
1514	hidnplayr	1427
		1428	.respond_ack:
		1429
1533	hidnplayr	1430	mov dl, TH_RST
1514	hidnplayr	1431
1533	hidnplayr	1432	push ebx
1529	hidnplayr	1433	call TCP_respond_segment
1533	hidnplayr	1434	pop ebx
1514	hidnplayr	1435
		1436	jmp .destroy_new_socket
		1437
		1438
		1439	.respond_syn:
		1440
1533	hidnplayr	1441	mov dl, TH_RST + TH_ACK
1514	hidnplayr	1442
1533	hidnplayr	1443	push ebx
		1444	call TCP_respond_socket
		1445	pop ebx
1514	hidnplayr	1446
		1447	jmp .destroy_new_socket
		1448
		1449	;-----
		1450	; Drop
		1451
		1452	align 4
		1453	.drop:
		1454
		1455	DEBUGF 1,"Dropping packet\n"
		1456
		1457	;;;; If debugging options are enabled, output the packet somwhere
		1458
		1459	.destroy_new_socket:
		1460
		1461	;;;; kill the newly created socket
		1462
		1463	call kernel_free
1529	hidnplayr	1464	add esp, 4
		1465	ret
1514	hidnplayr	1466
		1467
		1468
		1469
		1470
		1471
		1472	;---------------------------
		1473	;
		1474	; TCP_pull_out_of_band
		1475	;
		1476	; IN: eax =
		1477	; ebx = socket ptr
		1478	; edx = tcp packet ptr
		1479	;
		1480	; OUT: /
		1481	;
		1482	;---------------------------
		1483
		1484	align 4
		1485	TCP_pull_out_of_band:
		1486
		1487	DEBUGF 1,"TCP_pull_out_of_band\n"
		1488
		1489	;;;; 1282-1305
		1490
1318	hidnplayr	1491	ret
		1492
		1493
		1494
		1495	;-----------------------------------------------------------------
		1496	;
1514	hidnplayr	1497	; TCP_output
1318	hidnplayr	1498	;
1519	hidnplayr	1499	; IN: eax = socket pointer
1514	hidnplayr	1500	;
1318	hidnplayr	1501	; OUT: /
		1502	;
		1503	;-----------------------------------------------------------------
		1504	align 4
1514	hidnplayr	1505	TCP_output:
1318	hidnplayr	1506
1514	hidnplayr	1507	DEBUGF 1,"TCP_output, socket: %x\n", eax
1318	hidnplayr	1508
1514	hidnplayr	1509	; We'll detect the length of the data to be transmitted, and flags to be used
		1510	; If there is some data, or any critical controls to send (SYN / RST), then transmit
		1511	; Otherwise, investigate further
1318	hidnplayr	1512
1514	hidnplayr	1513	mov ebx, [eax + TCP_SOCKET.SND_MAX]
		1514	cmp ebx, [eax + TCP_SOCKET.SND_UNA]
		1515	jne .not_idle
1318	hidnplayr	1516
1514	hidnplayr	1517	mov ebx, [eax + TCP_SOCKET.t_idle]
		1518	cmp ebx, [eax + TCP_SOCKET.t_rxtcur]
		1519	jle .not_idle
1318	hidnplayr	1520
1514	hidnplayr	1521	; We have been idle for a while and no ACKS are expected to clock out any data we send..
		1522	; Slow start to get ack "clock" running again.
1318	hidnplayr	1523
1514	hidnplayr	1524	mov ebx, [eax + TCP_SOCKET.t_maxseg]
		1525	mov [eax + TCP_SOCKET.SND_CWND], ebx
1318	hidnplayr	1526
1514	hidnplayr	1527	.not_idle:
		1528	.again:
		1529	mov ebx, [eax + TCP_SOCKET.SND_NXT] ; calculate offset
		1530	sub ebx, [eax + TCP_SOCKET.SND_UNA] ;
1318	hidnplayr	1531
1514	hidnplayr	1532	mov ecx, [eax + TCP_SOCKET.SND_WND] ; determine window
		1533	cmp ecx, [eax + TCP_SOCKET.SND_CWND] ;
		1534	jl @f ;
		1535	mov ecx, [eax + TCP_SOCKET.SND_CWND] ;
		1536	@@: ;
1318	hidnplayr	1537
1529	hidnplayr	1538	call TCP_outflags ; in dl
1318	hidnplayr	1539
1514	hidnplayr	1540	; If in persist timeout with window of 0, send 1 byte.
		1541	; Otherwise, if window is small but nonzero, and timer expired,
		1542	; we will send what we can and go to transmit state
1318	hidnplayr	1543
1514	hidnplayr	1544	test [eax + TCP_SOCKET.t_force], -1
		1545	jz .no_persist_timeout
1318	hidnplayr	1546
1514	hidnplayr	1547	test ecx, ecx
		1548	jnz .no_zero_window
1255	hidnplayr	1549
1533	hidnplayr	1550	cmp ebx, [eax + STREAM_SOCKET.snd + RING_BUFFER.size]
1514	hidnplayr	1551	jge @f
1255	hidnplayr	1552
1514	hidnplayr	1553	and dl, not (TH_FIN) ; clear the FIN flag ??? how can it be set before?
1255	hidnplayr	1554
1514	hidnplayr	1555	@@:
		1556	inc ecx
		1557	jmp .no_persist_timeout
1255	hidnplayr	1558
1514	hidnplayr	1559	.no_zero_window:
1254	hidnplayr	1560
1529	hidnplayr	1561	mov [eax + TCP_SOCKET.timer_persist], 0 ;;;;
1514	hidnplayr	1562	mov [eax + TCP_SOCKET.t_rxtshift], 0
1254	hidnplayr	1563
1514	hidnplayr	1564	.no_persist_timeout:
1159	hidnplayr	1565
1514	hidnplayr	1566	;;;106
1159	hidnplayr	1567
1533	hidnplayr	1568	mov esi, [eax + STREAM_SOCKET.snd + RING_BUFFER.size]
1514	hidnplayr	1569	cmp esi, ecx
		1570	jl @f
		1571	mov esi, ecx
		1572	@@:
		1573	sub esi, ebx
1254	hidnplayr	1574
1514	hidnplayr	1575	cmp esi, -1
		1576	jne .not_minus_one
1159	hidnplayr	1577
1514	hidnplayr	1578	; If FIN has been set, but not ACKed, and we havent been called to retransmit,
		1579	; len (esi) will be -1
		1580	; Otherwise, window shrank after we sent into it.
		1581	; If window shrank to 0, cancel pending retransmit and pull SND_NXT back to (closed) window
		1582	; We will enter persist state below.
		1583	; If window didn't close completely, just wait for an ACK
1159	hidnplayr	1584
1514	hidnplayr	1585	xor esi, esi
1159	hidnplayr	1586
1514	hidnplayr	1587	test ecx, ecx
		1588	jnz @f
1159	hidnplayr	1589
1529	hidnplayr	1590	mov [eax + TCP_SOCKET.timer_retransmission], 0 ; cancel retransmit
1274	hidnplayr	1591
1514	hidnplayr	1592	push [eax + TCP_SOCKET.SND_UNA]
		1593	pop [eax + TCP_SOCKET.SND_NXT]
		1594	@@:
1254	hidnplayr	1595
1514	hidnplayr	1596	.not_minus_one:
1254	hidnplayr	1597
1514	hidnplayr	1598	;;; 124
1159	hidnplayr	1599
1514	hidnplayr	1600	cmp esi, [eax + TCP_SOCKET.t_maxseg]
		1601	jle @f
1274	hidnplayr	1602
1514	hidnplayr	1603	mov esi, [eax + TCP_SOCKET.t_maxseg]
		1604	;sendalot = 1
1274	hidnplayr	1605
1514	hidnplayr	1606	@@:
1274	hidnplayr	1607
1514	hidnplayr	1608	;;; 128
1274	hidnplayr	1609
1514	hidnplayr	1610	mov edi, [eax + TCP_SOCKET.SND_NXT]
		1611	add edi, esi ; len
		1612	sub edi, [eax + TCP_SOCKET.SND_UNA]
1533	hidnplayr	1613	add edi, [eax + STREAM_SOCKET.snd + RING_BUFFER.size]
1514	hidnplayr	1614	cmp edi, 0
		1615	jle @f
1274	hidnplayr	1616
1514	hidnplayr	1617	and dl, not (TH_FIN) ; clear the FIN flag
1159	hidnplayr	1618
1514	hidnplayr	1619	@@:
1159	hidnplayr	1620
		1621
1529	hidnplayr	1622	; set ecx to space available in receive buffer
		1623	; From now on, ecx will be the window we advertise to the other end
1159	hidnplayr	1624
1529	hidnplayr	1625	mov ecx, SOCKET_MAXDATA
1533	hidnplayr	1626	sub ecx, [eax + STREAM_SOCKET.rcv + RING_BUFFER.size]
1159	hidnplayr	1627
1514	hidnplayr	1628	;------------------------------
		1629	; Sender silly window avoidance
1159	hidnplayr	1630
1529	hidnplayr	1631	cmp ecx, [eax + TCP_SOCKET.t_maxseg]
1514	hidnplayr	1632	je .send
1274	hidnplayr	1633
1514	hidnplayr	1634	;;; TODO: 144-145
1274	hidnplayr	1635
1514	hidnplayr	1636	test [eax + TCP_SOCKET.t_force], -1
		1637	jnz .send
1274	hidnplayr	1638
1529	hidnplayr	1639	mov ebx, [eax + TCP_SOCKET.max_sndwnd]
		1640	shr ebx, 1
		1641	cmp ecx, ebx
		1642	jge .send
1274	hidnplayr	1643
1529	hidnplayr	1644	mov ebx, [eax + TCP_SOCKET.SND_NXT]
		1645	cmp ebx, [eax + TCP_SOCKET.SND_MAX]
		1646	jl .send
1254	hidnplayr	1647
1514	hidnplayr	1648	;----------------------------------------
		1649	; Check if a window update should be sent
1159	hidnplayr	1650
1529	hidnplayr	1651	test ecx, ecx ; window
		1652	jz .no_window
1159	hidnplayr	1653
1514	hidnplayr	1654	;;; TODO 154-172
1159	hidnplayr	1655
1514	hidnplayr	1656	.no_window:
1159	hidnplayr	1657
1514	hidnplayr	1658	;--------------------------
		1659	; Should a segment be sent?
1159	hidnplayr	1660
1534	hidnplayr	1661	test [eax + TCP_SOCKET.t_flags], TF_ACKNOW
1514	hidnplayr	1662	jnz .send
1159	hidnplayr	1663
1514	hidnplayr	1664	test dl, TH_SYN + TH_RST
		1665	jnz .send
1159	hidnplayr	1666
1534	hidnplayr	1667	mov ebx, [eax + TCP_SOCKET.SND_UP]
		1668	cmp ebx, [eax + TCP_SOCKET.SND_UNA]
1514	hidnplayr	1669	jg .send
1249	hidnplayr	1670
1514	hidnplayr	1671	test dl, TH_FIN
		1672	jz .enter_persist
1318	hidnplayr	1673
1534	hidnplayr	1674	test [eax + TCP_SOCKET.t_flags], TF_SENTFIN
1514	hidnplayr	1675	jnz .send
1254	hidnplayr	1676
1534	hidnplayr	1677	mov ebx, [eax + TCP_SOCKET.SND_NXT]
		1678	cmp ebx, [eax + TCP_SOCKET.SND_UNA]
1514	hidnplayr	1679	je .send
1254	hidnplayr	1680
1514	hidnplayr	1681	;--------------------
		1682	; Enter persist state
1318	hidnplayr	1683
1514	hidnplayr	1684	.enter_persist:
1318	hidnplayr	1685
1519	hidnplayr	1686	DEBUGF 1,"Entering persist state\n"
1318	hidnplayr	1687
1514	hidnplayr	1688	;--------------------------------------
		1689	; No reason to send a segment, just ret
1318	hidnplayr	1690
1514	hidnplayr	1691	DEBUGF 1,"No reason to send a segment\n"
1318	hidnplayr	1692
1514	hidnplayr	1693	ret
1318	hidnplayr	1694
		1695
1514	hidnplayr	1696	;-----------------------------------------------
		1697	;
		1698	; Send a segment
		1699	;
1529	hidnplayr	1700	; eax = socket pointer
1514	hidnplayr	1701	; dl = flags
		1702	;
		1703	;-----------------------------------------------
1318	hidnplayr	1704
1529	hidnplayr	1705	.send:
1318	hidnplayr	1706
1514	hidnplayr	1707	DEBUGF 1,"Preparing to send a segment\n"
1318	hidnplayr	1708
1529	hidnplayr	1709	mov edi, TCP_segment.Data ; edi will contain headersize
1318	hidnplayr	1710
1529	hidnplayr	1711	sub esp, 8 ; create some space on stack
		1712	push eax ; save this too..
		1713
1514	hidnplayr	1714	;------------------------------------
		1715	; Send options with first SYN segment
1318	hidnplayr	1716
1514	hidnplayr	1717	test dl, TH_SYN
		1718	jz .no_options
1318	hidnplayr	1719
1529	hidnplayr	1720	push [eax + TCP_SOCKET.ISS]
		1721	pop [eax + TCP_SOCKET.SND_NXT]
1318	hidnplayr	1722
1529	hidnplayr	1723	test [eax + TCP_SOCKET.t_flags], TF_NOOPT
1514	hidnplayr	1724	jnz .no_options
1318	hidnplayr	1725
1529	hidnplayr	1726	mov ecx, 1460
		1727	or ecx, TCP_OPT_MAXSEG shl 24 + 4 shl 16
		1728	bswap ecx
		1729	push ecx
		1730	add di, 4
1514	hidnplayr	1731
1529	hidnplayr	1732	test [eax + TCP_SOCKET.t_flags], TF_REQ_SCALE
1514	hidnplayr	1733	jz .no_syn
		1734
		1735	test dl, TH_ACK
		1736	jnz .scale_opt
		1737
1529	hidnplayr	1738	test [eax + TCP_SOCKET.t_flags], TF_RCVD_SCALE
1514	hidnplayr	1739	jz .no_syn
		1740
		1741	.scale_opt:
1529	hidnplayr	1742	movzx ecx, byte [eax + TCP_SOCKET.request_r_scale]
		1743	or ecx, TCP_OPT_WINDOW shl 24 + 4 shl 16 + TCP_OPT_NOP shl 8
		1744	bswap ecx
		1745	pushd ecx
1514	hidnplayr	1746	add di, 4
1159	hidnplayr	1747
1514	hidnplayr	1748	.no_syn:
1159	hidnplayr	1749
1514	hidnplayr	1750	;------------------------------------
		1751	; Make the timestamp option if needed
1159	hidnplayr	1752
1529	hidnplayr	1753	test [eax + TCP_SOCKET.t_flags], TF_REQ_TSTMP
1514	hidnplayr	1754	jz .no_timestamp
1159	hidnplayr	1755
1514	hidnplayr	1756	test dl, TH_RST
		1757	jnz .no_timestamp
		1758
		1759	test dl, TH_ACK
		1760	jz .timestamp
		1761
1529	hidnplayr	1762	test [eax + TCP_SOCKET.t_flags], TF_RCVD_TSTMP
1514	hidnplayr	1763	jz .no_timestamp
		1764
		1765	.timestamp:
1529	hidnplayr	1766	mov esi, [timer_ticks]
		1767	bswap esi
		1768	push esi
1514	hidnplayr	1769	pushw 0
1529	hidnplayr	1770	pushd TCP_OPT_TIMESTAMP + 10 shl 8 + TCP_OPT_NOP shl 16 + TCP_OPT_NOP shl 24
1514	hidnplayr	1771	add di, 10
		1772
		1773	.no_timestamp:
		1774	;; TODO: check if we dont exceed the max segment size
		1775
		1776	.no_options:
1529	hidnplayr	1777	; eax = socket ptr
		1778	; edx = flags
		1779	; ecx = data size
		1780	; edi = header size
		1781	; esi = snd ring buff ptr
1514	hidnplayr	1782
1533	hidnplayr	1783	mov ecx, [eax + STREAM_SOCKET.snd + RING_BUFFER.size]
		1784	cmp ecx, [eax + TCP_SOCKET.t_maxseg] ;;; right?
		1785	jle @f
		1786	mov ecx, [eax + TCP_SOCKET.t_maxseg]
		1787	@@:
1514	hidnplayr	1788	add ecx, edi ; total TCP segment size
		1789
1529	hidnplayr	1790	; Start by pushing all TCP header values in reverse order on stack
		1791	; (essentially, creating the tcp header!)
1514	hidnplayr	1792
1529	hidnplayr	1793	pushw 0 ; .UrgentPointer dw ?
		1794	pushw 0 ; .Checksum dw ?
		1795	pushw 0x00a0 ; .Window dw ? ;;;;;;;
		1796	shl edi, 2 ; .DataOffset db ? only 4 left-most bits
		1797	shl dx, 8
		1798	or dx, di ; .Flags db ?
		1799	pushw dx
		1800	shr edi, 2 ; .DataOffset db ? ;;;;
1514	hidnplayr	1801
1529	hidnplayr	1802	push [eax + TCP_SOCKET.RCV_NXT] ; .AckNumber dd ?
		1803	ntohld [esp]
1159	hidnplayr	1804
1529	hidnplayr	1805	push [eax + TCP_SOCKET.SND_NXT] ; .SequenceNumber dd ?
		1806	ntohld [esp]
1159	hidnplayr	1807
1529	hidnplayr	1808	push [eax + TCP_SOCKET.RemotePort] ; .DestinationPort dw ?
		1809	ntohlw [esp]
1249	hidnplayr	1810
1529	hidnplayr	1811	push [eax + TCP_SOCKET.LocalPort] ; .SourcePort dw ?
		1812	ntohlw [esp]
1274	hidnplayr	1813
1533	hidnplayr	1814	push edi ; header size
1274	hidnplayr	1815
1529	hidnplayr	1816	; Create the IP packet
		1817	mov ebx, [eax + IP_SOCKET.LocalIP] ; source ip
		1818	mov eax, [eax + IP_SOCKET.RemoteIP] ; dest ip
		1819	mov di, IP_PROTO_TCP shl 8 + 128
		1820	call IPv4_output
		1821	jz .fail
1274	hidnplayr	1822
1529	hidnplayr	1823	;-----------------------------------------
		1824	; Move TCP header from stack to TCP packet
1274	hidnplayr	1825
1533	hidnplayr	1826	push ecx
		1827	mov ecx, [esp+4]
		1828	lea esi, [esp+4+4]
1529	hidnplayr	1829	shr ecx, 2
		1830	rep movsd
1533	hidnplayr	1831	pop ecx ; full TCP packet size
1274	hidnplayr	1832
1533	hidnplayr	1833	pop esi ; headersize
		1834	add esp, esi
1254	hidnplayr	1835
1533	hidnplayr	1836	mov [esp + 4], eax ; packet ptr
1530	hidnplayr	1837	mov [esp + 4+4], edx ; packet size
1254	hidnplayr	1838
1533	hidnplayr	1839	mov edx, edi ; begin of data
		1840	sub edx, esi ; begin of packet (edi = begin of data)
		1841	push ecx
		1842	sub ecx, esi ; data size
1159	hidnplayr	1843
1514	hidnplayr	1844	;--------------
		1845	; Copy the data
1159	hidnplayr	1846
1529	hidnplayr	1847	; eax = ptr to ring struct
		1848	; ecx = buffer size
		1849	; edi = ptr to buffer
1249	hidnplayr	1850
1536	hidnplayr	1851	; test ecx, ecx
1533	hidnplayr	1852	mov eax, [esp+4] ; socket ptr
1536	hidnplayr	1853	add [eax + TCP_SOCKET.SND_NXT], ecx
		1854	add eax, STREAM_SOCKET.snd
1533	hidnplayr	1855	push edx
1529	hidnplayr	1856	call SOCKET_ring_read
1536	hidnplayr	1857	pop esi
		1858	pop ecx
1529	hidnplayr	1859	pop eax
1254	hidnplayr	1860
1533	hidnplayr	1861	test [esi + TCP_segment.Flags], TH_SYN + TH_FIN
		1862	jz @f
		1863	inc [eax + TCP_SOCKET.SND_NXT]
		1864	;;; TODO: update sentfin flag
		1865	@@:
1254	hidnplayr	1866
1533	hidnplayr	1867	mov edx, [eax + TCP_SOCKET.SND_NXT]
		1868	cmp edx, [eax + TCP_SOCKET.SND_MAX]
		1869	jle @f
		1870	mov [eax + TCP_SOCKET.SND_MAX], edx
		1871
		1872	;;;; TODO: time transmission (420)
		1873	@@:
		1874
		1875	;;; TODO: set retransmission timer
		1876
		1877	;--------------------
		1878	; Create the checksum
		1879
1529	hidnplayr	1880	DEBUGF 1,"checksum: ptr=%x size=%u\n", esi, ecx
1159	hidnplayr	1881
1529	hidnplayr	1882	TCP_checksum (eax + IP_SOCKET.LocalIP), (eax + IP_SOCKET.RemoteIP)
		1883	mov [esi+TCP_segment.Checksum], dx
		1884
1514	hidnplayr	1885	;----------------
		1886	; Send the packet
1159	hidnplayr	1887
1529	hidnplayr	1888	DEBUGF 1,"Sending TCP Packet to device %x\n", ebx
		1889	call [ebx + NET_DEVICE.transmit]
		1890	ret
1159	hidnplayr	1891
1514	hidnplayr	1892
1529	hidnplayr	1893	.fail:
		1894	pop ecx
		1895	add esp, ecx
1536	hidnplayr	1896	add esp, 4+8
1529	hidnplayr	1897	DEBUGF 1,"TCP_output: failed\n"
1159	hidnplayr	1898	ret
		1899
1529	hidnplayr	1900
		1901
1514	hidnplayr	1902	;-------------------------
		1903	;
		1904	; TCP_outflags
		1905	;
		1906	; IN: eax = socket ptr
		1907	;
		1908	; OUT: edx = flags
		1909	;
		1910	;-------------------------
1249	hidnplayr	1911	align 4
1514	hidnplayr	1912	TCP_outflags:
1254	hidnplayr	1913
1514	hidnplayr	1914	mov edx, [eax + TCP_SOCKET.t_state]
		1915	movzx edx, byte [edx + .flaglist]
1254	hidnplayr	1916
1514	hidnplayr	1917	DEBUGF 1,"TCP_outflags, socket: %x, flags: %x\n", eax, dl
		1918
1159	hidnplayr	1919	ret
		1920
1514	hidnplayr	1921	.flaglist:
1159	hidnplayr	1922
1514	hidnplayr	1923	db TH_RST + TH_ACK ; TCB_CLOSED
		1924	db 0 ; TCB_LISTEN
		1925	db TH_SYN ; TCB_SYN_SENT
		1926	db TH_SYN + TH_ACK ; TCB_SYN_RECEIVED
		1927	db TH_ACK ; TCB_ESTABLISHED
		1928	db TH_ACK ; TCB_CLOSE_WAIT
		1929	db TH_SYN + TH_ACK ; TCB_FIN_WAIT_1
		1930	db TH_SYN + TH_ACK ; TCB_CLOSING
		1931	db TH_SYN + TH_ACK ; TCB_LAST_ACK
		1932	db TH_ACK ; TCB_FIN_WAIT_2
		1933	db TH_ACK ; TCB_TIMED_WAIT
1249	hidnplayr	1934
1514	hidnplayr	1935
1529	hidnplayr	1936
		1937
1514	hidnplayr	1938	;-------------------------
		1939	;
		1940	; TCP_drop
		1941	;
		1942	; IN: eax = socket ptr
		1943	;
		1944	; OUT: /
		1945	;
		1946	;-------------------------
1249	hidnplayr	1947	align 4
1514	hidnplayr	1948	TCP_drop:
1254	hidnplayr	1949
1514	hidnplayr	1950	DEBUGF 1,"TCP_drop\n"
1254	hidnplayr	1951
1514	hidnplayr	1952	; cmp [eax + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		1953	; jl .no_syn_received
1159	hidnplayr	1954
1514	hidnplayr	1955	mov [eax + TCP_SOCKET.t_state], TCB_CLOSED
1159	hidnplayr	1956
1514	hidnplayr	1957	call TCP_output
1254	hidnplayr	1958
1514	hidnplayr	1959	; .no_syn_received:
		1960
1159	hidnplayr	1961	ret
		1962
		1963
1254	hidnplayr	1964
		1965
1159	hidnplayr	1966
1514	hidnplayr	1967	;---------------------------------------
		1968	;
1519	hidnplayr	1969	; The easy way to send an ACK/RST/keepalive segment
1514	hidnplayr	1970	;
1529	hidnplayr	1971	; TCP_respond_socket:
		1972	;
		1973	; IN: ebx = socket ptr
1519	hidnplayr	1974	; cl = flags
1514	hidnplayr	1975	;
1529	hidnplayr	1976	;--------------------------------------
1514	hidnplayr	1977	align 4
1529	hidnplayr	1978	TCP_respond_socket:
1254	hidnplayr	1979
1529	hidnplayr	1980	DEBUGF 1,"TCP_respond_socket\n"
1159	hidnplayr	1981
1519	hidnplayr	1982	;---------------------
		1983	; Create the IP packet
		1984
1529	hidnplayr	1985	push cx ebx
		1986	mov eax, [ebx + IP_SOCKET.RemoteIP]
		1987	mov ebx, [ebx + IP_SOCKET.LocalIP]
1519	hidnplayr	1988	mov ecx, TCP_segment.Data
1529	hidnplayr	1989	mov di , IP_PROTO_TCP shl 8 + 128
		1990	call IPv4_output
1519	hidnplayr	1991	test edi, edi
		1992	jz .error
1529	hidnplayr	1993	pop esi cx
		1994	push edx eax
1519	hidnplayr	1995
1529	hidnplayr	1996	;-----------------------------------------------
		1997	; Fill in the TCP header by using the socket ptr
1519	hidnplayr	1998
1529	hidnplayr	1999	mov ax, [esi + TCP_SOCKET.LocalPort]
		2000	rol ax, 8
		2001	stosw
		2002	mov ax, [esi + TCP_SOCKET.RemotePort]
		2003	rol ax, 8
		2004	stosw
		2005	mov eax, [esi + TCP_SOCKET.SND_NXT]
		2006	bswap eax
		2007	stosd
		2008	mov eax, [esi + TCP_SOCKET.RCV_NXT]
		2009	bswap eax
		2010	stosd
		2011	mov al, 0x50 ; Dataoffset: 20 bytes
		2012	stosb
		2013	mov al, cl
		2014	stosb
		2015	mov ax, [esi + TCP_SOCKET.RCV_WND]
		2016	rol ax, 8
		2017	stosw ; window
		2018	xor eax, eax
		2019	stosd ; checksum + urgentpointer
1519	hidnplayr	2020
		2021	;---------------------
		2022	; Fill in the checksum
		2023
		2024	.checksum:
1529	hidnplayr	2025	sub edi, TCP_segment.Data
		2026	mov ecx, TCP_segment.Data
		2027	xchg esi, edi
		2028	TCP_checksum (edi + IP_SOCKET.LocalIP), (esi + IP_SOCKET.RemoteIP)
		2029	mov [esi+TCP_segment.Checksum], dx
1519	hidnplayr	2030
		2031	;--------------------
		2032	; And send the segment
		2033
		2034	call [ebx + NET_DEVICE.transmit]
1159	hidnplayr	2035	ret
		2036
1519	hidnplayr	2037	.error:
1529	hidnplayr	2038	DEBUGF 1,"TCP_respond failed\n"
		2039	add esp, 2+4
1159	hidnplayr	2040
1519	hidnplayr	2041	ret
1514	hidnplayr	2042
1529	hidnplayr	2043
		2044
		2045	;-------------------------
		2046	; TCP_respond.segment:
		2047	;
		2048	; IN: edx = segment ptr (a previously received segment)
		2049	; cl = flags
		2050
		2051	align 4
		2052	TCP_respond_segment:
		2053
		2054	DEBUGF 1,"TCP_respond_segment\n"
		2055
		2056	;---------------------
		2057	; Create the IP packet
		2058
		2059	push cx edx
		2060	mov ebx, [edx - 20 + IPv4_Packet.SourceAddress] ;;;; and what if ip packet had options?!
		2061	mov eax, [edx - 20 + IPv4_Packet.DestinationAddress] ;;;
		2062	mov ecx, TCP_segment.Data
		2063	mov di , IP_PROTO_TCP shl 8 + 128
		2064	call IPv4_output
		2065	jz .error
1533	hidnplayr	2066	pop esi cx
1529	hidnplayr	2067
		2068	push edx eax
		2069
1519	hidnplayr	2070	;---------------------------------------------------
		2071	; Fill in the TCP header by using a received segment
		2072
		2073	mov ax, [esi + TCP_segment.DestinationPort]
		2074	rol ax, 8
		2075	stosw
		2076	mov ax, [esi + TCP_segment.SourcePort]
		2077	rol ax, 8
		2078	stosw
		2079	mov eax, [esi + TCP_segment.AckNumber]
		2080	bswap eax
		2081	stosd
		2082	xor eax, eax
		2083	stosd
		2084	mov al, 0x50 ; Dataoffset: 20 bytes
		2085	stosb
		2086	mov al, cl
		2087	stosb
		2088	mov ax, 1280
		2089	rol ax, 8
		2090	stosw ; window
		2091	xor eax, eax
		2092	stosd ; checksum + urgentpointer
		2093
1529	hidnplayr	2094	;---------------------
		2095	; Fill in the checksum
1519	hidnplayr	2096
1529	hidnplayr	2097	.checksum:
		2098	lea esi, [edi - TCP_segment.Data]
		2099	mov ecx, TCP_segment.Data
		2100	TCP_checksum (esi - 20 + IPv4_Packet.DestinationAddress), (esi - 20 + IPv4_Packet.DestinationAddress)
		2101	mov [esi+TCP_segment.Checksum], dx
1519	hidnplayr	2102
1529	hidnplayr	2103	;--------------------
		2104	; And send the segment
1519	hidnplayr	2105
1529	hidnplayr	2106	call [ebx + NET_DEVICE.transmit]
		2107	ret
1519	hidnplayr	2108
1529	hidnplayr	2109	.error:
		2110	DEBUGF 1,"TCP_respond failed\n"
		2111	add esp, 2+4
1519	hidnplayr	2112
		2113	ret
		2114
		2115
		2116
1254	hidnplayr	2117
		2118	;---------------------------------------------------------------------------
		2119	;
		2120	; TCP_API
		2121	;
		2122	; This function is called by system function 75
		2123	;
		2124	; IN: subfunction number in bl
		2125	; device number in bh
		2126	; ecx, edx, .. depends on subfunction
		2127	;
		2128	; OUT:
		2129	;
		2130	;---------------------------------------------------------------------------
		2131	align 4
		2132	TCP_API:
		2133
		2134	movzx eax, bh
		2135	shl eax, 2
		2136
		2137	test bl, bl
		2138	jz .packets_tx ; 0
		2139	dec bl
		2140	jz .packets_rx ; 1
		2141
		2142	.error:
		2143	mov eax, -1
		2144	ret
		2145
		2146	.packets_tx:
1514	hidnplayr	2147	add eax, TCP_segments_tx
1254	hidnplayr	2148	mov eax, [eax]
		2149	ret
		2150
		2151	.packets_rx:
1514	hidnplayr	2152	add eax, TCP_segments_rx
1254	hidnplayr	2153	mov eax, [eax]
		2154	ret

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(root)/kernel/branches/net/network/tcp.inc – Rev 1542