WebSVN – Kolibri OS – Blame – /kernel/trunk/network/tcp_input.inc

Rev	Author	Line No.	Line
3545	hidnplayr	1	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
		2	;; ;;
6910	hidnplayr	3	;; Copyright (C) KolibriOS team 2004-2017. All rights reserved. ;;
3545	hidnplayr	4	;; Distributed under terms of the GNU General Public License ;;
		5	;; ;;
		6	;; Part of the TCP/IP network stack for KolibriOS ;;
		7	;; ;;
		8	;; Written by hidnplayr@kolibrios.org ;;
		9	;; ;;
5133	hidnplayr	10	;; Based on the algorithms used in 4.4BSD ;;
3545	hidnplayr	11	;; ;;
		12	;; GNU GENERAL PUBLIC LICENSE ;;
		13	;; Version 2, June 1991 ;;
		14	;; ;;
		15	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
		16
4850	mario79	17	$Revision: 6915 $
3545	hidnplayr	18
6476	hidnplayr	19	TCP_BIT_NEEDOUTPUT = 1 shl 0
		20	TCP_BIT_TIMESTAMP = 1 shl 1
		21	TCP_BIT_DROPSOCKET = 1 shl 2
		22	TCP_BIT_FIN_IS_ACKED = 1 shl 3
		23
5976	hidnplayr	24	;-----------------------------------------------------------------;
		25	; ;
		26	; TCP_input: Add a segment to the incoming TCP queue. ;
		27	; ;
		28	; IN: [esp] = ptr to buffer ;
		29	; ebx = ptr to device struct ;
		30	; ecx = TCP segment size ;
		31	; edx = ptr to IPv4 header ;
		32	; esi = ptr to TCP segment ;
		33	; edi = interface number*4 ;
		34	; ;
		35	; OUT: / ;
		36	; ;
		37	;-----------------------------------------------------------------;
3545	hidnplayr	38	align 4
6011	hidnplayr	39	tcp_input:
6908	ashmew2	40
3545	hidnplayr	41	; record the current time
5522	hidnplayr	42	push [timer_ticks] ; in 1/100 seconds
5842	hidnplayr	43	push ebx ecx esi edx ; mind the order (see TCP_queue_entry struct)
3545	hidnplayr	44	mov esi, esp
		45
5842	hidnplayr	46	push edi
3545	hidnplayr	47	add_to_queue TCP_queue, TCP_QUEUE_SIZE, sizeof.TCP_queue_entry, .fail
5842	hidnplayr	48	pop edi
3545	hidnplayr	49	add esp, sizeof.TCP_queue_entry
		50
3644	hidnplayr	51	inc [TCP_segments_rx + edi]
		52
3545	hidnplayr	53	xor edx, edx
		54	mov eax, [TCP_input_event]
		55	mov ebx, [eax + EVENT.id]
		56	xor esi, esi
		57	call raise_event
		58
		59	ret
		60
		61	.fail:
5842	hidnplayr	62	pop edi
3556	hidnplayr	63	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP incoming queue is full, discarding packet!\n"
3545	hidnplayr	64
6011	hidnplayr	65	call net_ptr_to_num4
3644	hidnplayr	66	inc [TCP_segments_missed + edi]
3545	hidnplayr	67
5841	hidnplayr	68	add esp, sizeof.TCP_queue_entry - 4
6011	hidnplayr	69	call net_buff_free
3545	hidnplayr	70	ret
		71
		72
6476	hidnplayr	73	;-----------------------------------------------------------------;
		74	; ;
		75	; TCP_process_input: Process segments from the incoming TCP queue.;
		76	; ;
		77	; IN: / ;
		78	; OUT: / ;
		79	; ;
		80	;-----------------------------------------------------------------;
3545	hidnplayr	81	align 4
6011	hidnplayr	82	proc tcp_process_input
3545	hidnplayr	83
4339	hidnplayr	84	locals
		85	dataoffset dd ?
4344	hidnplayr	86	timestamp dd ?
4347	hidnplayr	87	temp_bits db ?
6910	hidnplayr	88	device dd ?
4339	hidnplayr	89	endl
		90
3545	hidnplayr	91	xor esi, esi
		92	mov ecx, MANUAL_DESTROY
		93	call create_event
		94	mov [TCP_input_event], eax
		95
		96	.wait:
		97	mov eax, [TCP_input_event]
		98	mov ebx, [eax + EVENT.id]
		99	call wait_event
		100
		101	.loop:
		102	get_from_queue TCP_queue, TCP_QUEUE_SIZE, sizeof.TCP_queue_entry, .wait
		103
		104	push [esi + TCP_queue_entry.timestamp]
4344	hidnplayr	105	pop [timestamp]
3545	hidnplayr	106	push [esi + TCP_queue_entry.buffer_ptr]
		107
		108	mov ebx, [esi + TCP_queue_entry.device_ptr]
6910	hidnplayr	109	mov [device], ebx
3545	hidnplayr	110	mov ecx, [esi + TCP_queue_entry.segment_size]
6910	hidnplayr	111	mov edi, [esi + TCP_queue_entry.ip_ptr] ; ptr to ipv4 header
3545	hidnplayr	112	mov esi, [esi + TCP_queue_entry.segment_ptr] ; change esi last
		113
6908	ashmew2	114	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: size=%u time=%d\n", ecx, [timer_ticks]
3545	hidnplayr	115
		116	mov edx, esi
		117
6476	hidnplayr	118	; Verify the checksum (if not already done by hw)
3545	hidnplayr	119
4388	hidnplayr	120	test [ebx + NET_DEVICE.hwacc], NET_HWACC_TCP_IPv4_IN
		121	jnz .checksum_ok
3545	hidnplayr	122
		123	push ecx esi
		124	pushw [esi + TCP_header.Checksum]
		125	mov [esi + TCP_header.Checksum], 0
6011	hidnplayr	126	tcp_checksum (edi+IPv4_header.SourceAddress), (edi+IPv4_header.DestinationAddress)
5842	hidnplayr	127	pop cx ; previous checksum
3545	hidnplayr	128	cmp cx, dx
		129	pop edx ecx
		130	jne .drop_no_socket
		131	.checksum_ok:
		132
		133	; Verify the data offset
6476	hidnplayr	134
4339	hidnplayr	135	movzx eax, [edx + TCP_header.DataOffset]
		136	and al, 0xf0 ; Calculate TCP segment header size (throwing away unused reserved bits in TCP header)
		137	shr al, 2
		138	cmp al, sizeof.TCP_header ; Now see if it's at least the size of a standard TCP header
		139	jb .drop_no_socket ; If not, drop the packet
		140	mov [dataoffset], eax
3545	hidnplayr	141
		142	sub ecx, eax ; substract TCP header size from total segment size
		143	jb .drop_no_socket ; If total segment size is less then the advertised header size, drop packet
6908	ashmew2	144	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: %u bytes of data\n", ecx
3545	hidnplayr	145
		146	;-------------------------------------------
		147	; Convert Big-endian values to little endian
		148
		149	ntohd [edx + TCP_header.SequenceNumber]
		150	ntohd [edx + TCP_header.AckNumber]
		151
		152	ntohw [edx + TCP_header.Window]
		153	ntohw [edx + TCP_header.UrgentPointer]
		154
6476	hidnplayr	155	;-----------------------------------------------------------------------------------
		156	;
3545	hidnplayr	157	; Find the socket pointer
6476	hidnplayr	158	;
		159	;-----------------------------------------------------------------------------------
3545	hidnplayr	160
		161	; IP Packet TCP Destination Port = local Port
		162	; (IP Packet SenderAddress = Remote IP) OR (Remote IP = 0)
		163	; (IP Packet TCP Source Port = remote Port) OR (remote Port = 0)
		164
		165	.findpcb:
3647	hidnplayr	166	pusha
		167	mov ecx, socket_mutex
		168	call mutex_lock
		169	popa
		170
3545	hidnplayr	171	mov ebx, net_sockets
		172	mov si, [edx + TCP_header.DestinationPort]
		173
		174	.socket_loop:
		175	mov ebx, [ebx + SOCKET.NextPtr]
		176	or ebx, ebx
3647	hidnplayr	177	jz .no_socket ;respond_seg_reset
3545	hidnplayr	178
		179	cmp [ebx + SOCKET.Domain], AF_INET4
		180	jne .socket_loop
		181
		182	cmp [ebx + SOCKET.Protocol], IP_PROTO_TCP
		183	jne .socket_loop
		184
		185	cmp [ebx + TCP_SOCKET.LocalPort], si
		186	jne .socket_loop
		187
		188	mov eax, [ebx + IP_SOCKET.RemoteIP]
5842	hidnplayr	189	cmp eax, [edi + IPv4_header.SourceAddress]
3545	hidnplayr	190	je @f
		191	test eax, eax
		192	jnz .socket_loop
		193	@@:
		194
		195	mov ax, [ebx + TCP_SOCKET.RemotePort]
		196	cmp [edx + TCP_header.SourcePort], ax
		197	je .found_socket
		198	test ax, ax
		199	jnz .socket_loop
		200	.found_socket: ; ebx now contains the socketpointer
3647	hidnplayr	201	pusha
		202	mov ecx, socket_mutex
		203	call mutex_unlock
		204	popa
		205
6908	ashmew2	206	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: socket ptr=%x state=%u flags=%x\n", ebx, [ebx + TCP_SOCKET.t_state], [edx + TCP_header.Flags]:2
3545	hidnplayr	207
		208	;----------------------------
		209	; Check if socket isnt closed
		210
		211	cmp [ebx + TCP_SOCKET.t_state], TCPS_CLOSED
		212	je .drop_no_socket
		213
		214	;----------------
		215	; Lock the socket
		216
		217	pusha
		218	lea ecx, [ebx + SOCKET.mutex]
		219	call mutex_lock
		220	popa
		221
6908	ashmew2	222	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: socket locked\n"
3545	hidnplayr	223
		224	;---------------------------
		225	; disable all temporary bits
		226
4347	hidnplayr	227	mov [temp_bits], 0
3545	hidnplayr	228
		229	;---------------------------------------
		230	; unscale the window into a 32 bit value
		231
		232	movzx eax, [edx + TCP_header.Window]
		233	push ecx
		234	mov cl, [ebx + TCP_SOCKET.SND_SCALE]
		235	shl eax, cl
6476	hidnplayr	236	mov dword[edx + TCP_header.Window], eax ; word after window is checksum, we dont need checksum anymore
3545	hidnplayr	237	pop ecx
		238
6476	hidnplayr	239	;-----------------------------------------------------------------------------------
		240	;
		241	; Accept incoming connections
		242	;
		243	;-----------------------------------------------------------------------------------
3545	hidnplayr	244
		245	test [ebx + SOCKET.options], SO_ACCEPTCON
		246	jz .no_accept
		247
6908	ashmew2	248	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Accepting new connection\n"
3545	hidnplayr	249
6476	hidnplayr	250	; Unlock current socket
		251
3545	hidnplayr	252	pusha
		253	lea ecx, [ebx + SOCKET.mutex]
		254	call mutex_unlock
		255	popa
		256
6476	hidnplayr	257	; Fork it
		258
5842	hidnplayr	259	push ecx edx esi edi
6011	hidnplayr	260	call socket_fork
3545	hidnplayr	261	pop edi esi edx ecx
		262
		263	test eax, eax
		264	jz .drop_no_socket
		265
6476	hidnplayr	266	; Success! Use the new socket from now on (it is already locked)
		267
3545	hidnplayr	268	mov ebx, eax
		269
4347	hidnplayr	270	mov [temp_bits], TCP_BIT_DROPSOCKET
3545	hidnplayr	271
5842	hidnplayr	272	push [edi + IPv4_header.DestinationAddress]
3545	hidnplayr	273	pop [ebx + IP_SOCKET.LocalIP]
		274
		275	push [edx + TCP_header.DestinationPort]
		276	pop [ebx + TCP_SOCKET.LocalPort]
		277
		278	mov [ebx + TCP_SOCKET.t_state], TCPS_LISTEN
		279	.no_accept:
		280
		281
		282	;-------------------------------------
		283	; Reset idle timer and keepalive timer
		284
		285	mov [ebx + TCP_SOCKET.t_idle], 0
		286	mov [ebx + TCP_SOCKET.timer_keepalive], TCP_time_keep_idle
3600	hidnplayr	287	or [ebx + TCP_SOCKET.timer_flags], timer_flag_keepalive
3545	hidnplayr	288
6476	hidnplayr	289	;-----------------------------------------------------------------------------------
		290	;
3545	hidnplayr	291	; Process TCP options
6476	hidnplayr	292	;
		293	;-----------------------------------------------------------------------------------
3545	hidnplayr	294
4339	hidnplayr	295	;;; FIXME: for LISTEN, options should be called after we determined route, we need it for MSS
		296	;;; cmp [ebx + TCP_SOCKET.t_state], TCPS_LISTEN ; no options when in listen state
		297	;;; jz .not_uni_xfer ; also no header prediction
		298
3545	hidnplayr	299	push ecx
		300
4339	hidnplayr	301	mov ecx, [dataoffset]
6476	hidnplayr	302	cmp ecx, sizeof.TCP_header ; Does header contain any options?
3545	hidnplayr	303	je .no_options
		304
6908	ashmew2	305	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Segment has options\n"
3545	hidnplayr	306
		307	add ecx, edx
		308	lea esi, [edx + sizeof.TCP_header]
		309
		310	.opt_loop:
		311	cmp esi, ecx ; are we scanning outside of header?
		312	jae .no_options
		313	lodsb
		314	cmp al, TCP_OPT_EOL ; end of option list?
		315	je .no_options
		316	cmp al, TCP_OPT_NOP
		317	je .opt_loop
		318	cmp al, TCP_OPT_MAXSEG
		319	je .opt_maxseg
		320	cmp al, TCP_OPT_WINDOW
		321	je .opt_window
		322	cmp al, TCP_OPT_SACK_PERMIT
		323	je .opt_sack_permit
		324	; cmp al, TCP_OPT_SACK
		325	; je .opt_sack
		326	cmp al, TCP_OPT_TIMESTAMP
		327	je .opt_timestamp
6908	ashmew2	328	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: unknown option:%u\n", al
3545	hidnplayr	329	jmp .no_options ; If we reach here, some unknown options were received, skip them all!
		330
		331	.opt_maxseg:
		332	lodsb
		333	cmp al, 4
		334	jne .no_options ; error occured, ignore all options!
		335
		336	test [edx + TCP_header.Flags], TH_SYN
		337	jz @f
		338
4339	hidnplayr	339	xor eax, eax
3545	hidnplayr	340	lodsw
		341	rol ax, 8
6908	ashmew2	342	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Maxseg=%u\n", eax
6011	hidnplayr	343	call tcp_mss
3545	hidnplayr	344	@@:
		345	jmp .opt_loop
		346
		347
		348	.opt_window:
		349	lodsb
		350	cmp al, 3
		351	jne .no_options
		352
		353	test [edx + TCP_header.Flags], TH_SYN
		354	jz @f
		355
6908	ashmew2	356	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Got window scale option\n"
3545	hidnplayr	357	or [ebx + TCP_SOCKET.t_flags], TF_RCVD_SCALE
		358
		359	lodsb
		360	mov [ebx + TCP_SOCKET.SND_SCALE], al
		361	;;;;; TODO
		362
		363	@@:
		364	jmp .opt_loop
		365
		366
		367	.opt_sack_permit:
		368	lodsb
		369	cmp al, 2
		370	jne .no_options
		371
		372	test [edx + TCP_header.Flags], TH_SYN
		373	jz @f
		374
6908	ashmew2	375	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Selective Acknowledgement permitted\n"
3545	hidnplayr	376	or [ebx + TCP_SOCKET.t_flags], TF_SACK_PERMIT
		377
		378	@@:
		379	jmp .opt_loop
		380
		381
		382	.opt_timestamp:
		383	lodsb
		384	cmp al, 10 ; length must be 10
		385	jne .no_options
		386
6908	ashmew2	387	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Got timestamp option\n"
3545	hidnplayr	388
		389	test [edx + TCP_header.Flags], TH_SYN
		390	jz @f
		391	or [ebx + TCP_SOCKET.t_flags], TF_RCVD_TSTMP
		392	@@:
		393
		394	lodsd
4344	hidnplayr	395	bswap eax
3545	hidnplayr	396	mov [ebx + TCP_SOCKET.ts_val], eax
		397	lodsd ; timestamp echo reply
		398	mov [ebx + TCP_SOCKET.ts_ecr], eax
4347	hidnplayr	399	or [temp_bits], TCP_BIT_TIMESTAMP
3545	hidnplayr	400
		401	; Since we have a timestamp, lets do the paws test right away!
		402
		403	test [edx + TCP_header.Flags], TH_RST
		404	jnz .no_paws
		405
		406	mov eax, [ebx + TCP_SOCKET.ts_recent]
		407	test eax, eax
		408	jz .no_paws
		409	cmp eax, [ebx + TCP_SOCKET.ts_val]
4344	hidnplayr	410	jbe .no_paws
3545	hidnplayr	411
6908	ashmew2	412	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: PAWS: detected an old segment\n"
3545	hidnplayr	413
4344	hidnplayr	414	mov eax, [timestamp]
3545	hidnplayr	415	sub eax, [ebx + TCP_SOCKET.ts_recent_age]
		416
		417	pop ecx
		418	cmp eax, TCP_PAWS_IDLE
5442	hidnplayr	419	jle .paws_drop
3545	hidnplayr	420	push ecx
		421	mov [ebx + TCP_SOCKET.ts_recent], 0 ; timestamp was invalid, fix it.
		422	.no_paws:
		423	jmp .opt_loop
		424
5442	hidnplayr	425	.paws_drop:
6476	hidnplayr	426	inc [TCPS_rcvduppack]
5442	hidnplayr	427	add [TCPS_rcvdupbyte], ecx
		428	inc [TCPS_pawsdrop]
		429	jmp .drop_after_ack
		430
3545	hidnplayr	431	.no_options:
		432
		433	pop ecx
		434
6476	hidnplayr	435	;-----------------------------------------------------------------------------------
		436	;
		437	; Header prediction
		438	;
		439	;-----------------------------------------------------------------------------------
3545	hidnplayr	440
6476	hidnplayr	441	; According to Van Jacobson, there are two common cases for an uni-directional data transfer.
3545	hidnplayr	442	;
		443	; General rule: the packets has no control flags, is in-sequence,
		444	; window width didnt change and we're not retransmitting.
		445	;
		446	; Second rules:
		447	; - If the length is 0 and the ACK moved forward, we're the sender side of the transfer.
		448	; In this case we'll free the ACK'ed data and notify higher levels that we have free space in buffer
		449	;
		450	; - If the length is not 0 and the ACK didn't move, we're the receiver side of the transfer.
		451	; If the packets are in order (data queue is empty), add the data to the socket buffer and request a delayed ACK
		452
		453	cmp [ebx + TCP_SOCKET.t_state], TCPS_ESTABLISHED
		454	jnz .not_uni_xfer
		455
		456	test [edx + TCP_header.Flags], TH_SYN + TH_FIN + TH_RST + TH_URG
		457	jnz .not_uni_xfer
		458
		459	test [edx + TCP_header.Flags], TH_ACK
		460	jz .not_uni_xfer
		461
		462	mov eax, [edx + TCP_header.SequenceNumber]
		463	cmp eax, [ebx + TCP_SOCKET.RCV_NXT]
		464	jne .not_uni_xfer
		465
6476	hidnplayr	466	mov eax, dword[edx + TCP_header.Window]
3545	hidnplayr	467	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		468	jne .not_uni_xfer
		469
		470	mov eax, [ebx + TCP_SOCKET.SND_NXT]
		471	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		472	jne .not_uni_xfer
		473
		474	;---------------------------------------
		475	; check if we are sender in the uni-xfer
		476
		477	; If the following 4 conditions are all true, this segment is a pure ACK.
		478	;
		479	; - The segment contains no data.
6476	hidnplayr	480
3545	hidnplayr	481	test ecx, ecx
		482	jnz .not_sender
		483
		484	; - The congestion window is greater than or equal to the current send window.
		485	; 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.
6476	hidnplayr	486
3545	hidnplayr	487	mov eax, [ebx + TCP_SOCKET.SND_CWND]
		488	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		489	jb .not_uni_xfer
		490
		491	; - The acknowledgment field in the segment is less than or equal to the maximum sequence number sent.
6476	hidnplayr	492
3545	hidnplayr	493	mov eax, [edx + TCP_header.AckNumber]
		494	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		495	ja .not_uni_xfer
		496
		497	; - The acknowledgment field in the segment is greater than the largest unacknowledged sequence number.
6476	hidnplayr	498
3545	hidnplayr	499	sub eax, [ebx + TCP_SOCKET.SND_UNA]
		500	jbe .not_uni_xfer
		501
6908	ashmew2	502	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Header prediction: we are sender\n"
3545	hidnplayr	503
		504	;---------------------------------
		505	; Packet is a pure ACK, process it
		506
6476	hidnplayr	507	inc [TCPS_predack]
		508
		509	inc [TCPS_rcvackpack]
		510	add [TCPS_rcvackbyte], eax
		511
3545	hidnplayr	512	; Delete acknowledged bytes from send buffer
6476	hidnplayr	513
3545	hidnplayr	514	pusha
		515	mov ecx, eax
		516	lea eax, [ebx + STREAM_SOCKET.snd]
6011	hidnplayr	517	call socket_ring_free
3545	hidnplayr	518	popa
		519
		520	; Update RTT estimators
		521
4347	hidnplayr	522	test [temp_bits], TCP_BIT_TIMESTAMP
3545	hidnplayr	523	jz .no_timestamp_rtt
4344	hidnplayr	524	mov eax, [timestamp]
3545	hidnplayr	525	sub eax, [ebx + TCP_SOCKET.ts_ecr]
		526	inc eax
6011	hidnplayr	527	call tcp_xmit_timer
3545	hidnplayr	528	jmp .rtt_done
5976	hidnplayr	529	.no_timestamp_rtt:
3545	hidnplayr	530
		531	cmp [ebx + TCP_SOCKET.t_rtt], 0
		532	je .rtt_done
		533	mov eax, [edx + TCP_header.AckNumber]
		534	cmp eax, [ebx + TCP_SOCKET.t_rtseq]
		535	jbe .rtt_done
		536	mov eax, [ebx + TCP_SOCKET.t_rtt]
6011	hidnplayr	537	call tcp_xmit_timer
3545	hidnplayr	538	.rtt_done:
		539
		540	; update window pointers
6476	hidnplayr	541
3545	hidnplayr	542	mov eax, [edx + TCP_header.AckNumber]
		543	mov [ebx + TCP_SOCKET.SND_UNA], eax
		544
		545	; Stop retransmit timer
6476	hidnplayr	546
3600	hidnplayr	547	and [ebx + TCP_SOCKET.timer_flags], not timer_flag_retransmission
3545	hidnplayr	548
		549	; Unlock the socket
6476	hidnplayr	550
3545	hidnplayr	551	pusha
		552	lea ecx, [ebx + SOCKET.mutex]
		553	call mutex_unlock
		554	popa
		555
		556	; Awaken waiting processes
6476	hidnplayr	557
3545	hidnplayr	558	mov eax, ebx
6011	hidnplayr	559	call socket_notify
3545	hidnplayr	560
		561	; Generate more output
6476	hidnplayr	562
6011	hidnplayr	563	call tcp_output
3545	hidnplayr	564
		565	jmp .drop_no_socket
		566
		567	;-------------------------------------------------
		568	; maybe we are the receiver in the uni-xfer then..
		569
		570	.not_sender:
6476	hidnplayr	571
3545	hidnplayr	572	; - The amount of data in the segment is greater than 0 (data count is in ecx)
6476	hidnplayr	573	; - The acknowledgment field equals the largest unacknowledged sequence number. This means no data is acknowledged by this segment.
3545	hidnplayr	574
		575	mov eax, [edx + TCP_header.AckNumber]
		576	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
		577	jne .not_uni_xfer
		578
5133	hidnplayr	579	; - The reassembly list of out-of-order segments for the connection is empty.
6476	hidnplayr	580
5133	hidnplayr	581	cmp [ebx + TCP_SOCKET.seg_next], 0
		582	jne .not_uni_xfer
3545	hidnplayr	583
		584	; Complete processing of received data
		585
6908	ashmew2	586	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Header prediction: we are receiving %u bytes\n", ecx
3545	hidnplayr	587
4339	hidnplayr	588	mov esi, [dataoffset]
3545	hidnplayr	589	add esi, edx
		590	lea eax, [ebx + STREAM_SOCKET.rcv]
6011	hidnplayr	591	call socket_ring_write ; Add the data to the socket buffer
4344	hidnplayr	592	add [ebx + TCP_SOCKET.RCV_NXT], ecx ; Update sequence number with number of bytes we have copied
3545	hidnplayr	593
		594	mov eax, ebx
6011	hidnplayr	595	call socket_notify
3545	hidnplayr	596
		597	or [ebx + TCP_SOCKET.t_flags], TF_DELACK ; Set delayed ack flag
		598
		599	jmp .drop
		600
		601
6476	hidnplayr	602	;-----------------------------------------------------------------------------------
		603	;
		604	; TCP segment processing, the slow way
		605	;
		606	;-----------------------------------------------------------------------------------
		607
3545	hidnplayr	608	.not_uni_xfer:
6908	ashmew2	609	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Header prediction failed\n"
3545	hidnplayr	610
		611	; Calculate receive window size
6476	hidnplayr	612
3545	hidnplayr	613	push edx
6413	hidnplayr	614	mov eax, SOCKET_BUFFER_SIZE
3545	hidnplayr	615	sub eax, [ebx + STREAM_SOCKET.rcv.size]
6908	ashmew2	616	DEBUGF DEBUG_NETWORK_VERBOSE, "Space in receive buffer=%d\n", eax
3545	hidnplayr	617	mov edx, [ebx + TCP_SOCKET.RCV_ADV]
		618	sub edx, [ebx + TCP_SOCKET.RCV_NXT]
6908	ashmew2	619	DEBUGF DEBUG_NETWORK_VERBOSE, "Current advertised window=%d\n", edx
3545	hidnplayr	620	cmp eax, edx
		621	jg @f
		622	mov eax, edx
		623	@@:
6908	ashmew2	624	DEBUGF DEBUG_NETWORK_VERBOSE, "Receive window size=%d\n", eax
3545	hidnplayr	625	mov [ebx + TCP_SOCKET.RCV_WND], eax
		626	pop edx
		627
		628	; If we are in listen or syn_sent state, go to that specific code right away
		629
		630	cmp [ebx + TCP_SOCKET.t_state], TCPS_LISTEN
6476	hidnplayr	631	je .state_listen
3545	hidnplayr	632
		633	cmp [ebx + TCP_SOCKET.t_state], TCPS_SYN_SENT
6476	hidnplayr	634	je .state_syn_sent
3545	hidnplayr	635
6476	hidnplayr	636	;-----------------------------------------------------------------------------------
		637	;
		638	; Trim any data not in window
		639	;
		640	;-----------------------------------------------------------------------------------
3545	hidnplayr	641
6476	hidnplayr	642	;-------------------------------------------------
		643	; Check for duplicate data at beginning of segment
3545	hidnplayr	644
4339	hidnplayr	645	; Calculate number of bytes we need to drop
6476	hidnplayr	646
3545	hidnplayr	647	mov eax, [ebx + TCP_SOCKET.RCV_NXT]
		648	sub eax, [edx + TCP_header.SequenceNumber]
		649	jle .no_duplicate
		650
6908	ashmew2	651	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: %u bytes duplicate data!\n", eax
3545	hidnplayr	652
6476	hidnplayr	653	; Check for duplicate SYN
		654
3545	hidnplayr	655	test [edx + TCP_header.Flags], TH_SYN
		656	jz .no_dup_syn
		657
6908	ashmew2	658	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: got duplicate syn\n"
3545	hidnplayr	659
		660	and [edx + TCP_header.Flags], not (TH_SYN)
		661	inc [edx + TCP_header.SequenceNumber]
		662
		663	cmp [edx + TCP_header.UrgentPointer], 1
		664	jbe @f
		665	dec [edx + TCP_header.UrgentPointer]
		666	jmp .dup_syn
		667	@@:
		668	and [edx + TCP_header.Flags], not (TH_URG)
		669	.dup_syn:
		670	dec eax
		671	.no_dup_syn:
		672
6476	hidnplayr	673	;-----------------------------------
		674	; Check for entire duplicate segment
		675
3545	hidnplayr	676	cmp eax, ecx ; eax holds number of bytes to drop, ecx is data size
6476	hidnplayr	677	jb .no_complete_dup
3545	hidnplayr	678	jnz @f
		679	test [edx + TCP_header.Flags], TH_FIN
6476	hidnplayr	680	jnz .no_complete_dup
3545	hidnplayr	681	@@:
		682
		683	; Any valid FIN must be to the left of the window.
		684	; At this point the FIN must be out of sequence or a duplicate, drop it
6476	hidnplayr	685
3545	hidnplayr	686	and [edx + TCP_header.Flags], not TH_FIN
		687
6476	hidnplayr	688	; send an ACK to resynchronize and drop any data.
3545	hidnplayr	689	; But keep on processing for RST or ACK
6476	hidnplayr	690
3545	hidnplayr	691	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
		692	mov eax, ecx
		693
6476	hidnplayr	694	inc [TCPS_rcvduppack]
		695	add [TCPS_rcvdupbyte], eax
		696	jmp .dup_processed
		697	.no_complete_dup:
5442	hidnplayr	698	inc [TCPS_rcvpartduppack]
6476	hidnplayr	699	add [TCPS_rcvpartdupbyte], eax
		700	.dup_processed:
5442	hidnplayr	701
3545	hidnplayr	702	;-----------------------------------------------
		703	; Remove duplicate data and update urgent offset
		704
6908	ashmew2	705	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: trimming duplicate data\n"
4339	hidnplayr	706
		707	; Trim data from left side of window
6476	hidnplayr	708
4339	hidnplayr	709	add [dataoffset], eax
3545	hidnplayr	710	add [edx + TCP_header.SequenceNumber], eax
		711	sub ecx, eax
		712
		713	sub [edx + TCP_header.UrgentPointer], ax
		714	jg @f
		715	and [edx + TCP_header.Flags], not (TH_URG)
		716	mov [edx + TCP_header.UrgentPointer], 0
		717	@@:
6476	hidnplayr	718	.no_duplicate:
3545	hidnplayr	719
		720	;--------------------------------------------------
4339	hidnplayr	721	; Handle data that arrives after process terminates
3545	hidnplayr	722
4339	hidnplayr	723	cmp [ebx + SOCKET.PID], 0 ;;; TODO: use socket flags instead??
3545	hidnplayr	724	jne .not_terminated
		725	cmp [ebx + TCP_SOCKET.t_state], TCPS_CLOSE_WAIT
		726	jbe .not_terminated
		727	test ecx, ecx
		728	jz .not_terminated
		729
		730	mov eax, ebx
6011	hidnplayr	731	call tcp_close
5442	hidnplayr	732	inc [TCPS_rcvafterclose]
3545	hidnplayr	733	jmp .respond_seg_reset
6476	hidnplayr	734	.not_terminated:
3545	hidnplayr	735
		736	;----------------------------------------
4339	hidnplayr	737	; Remove data beyond right edge of window
3545	hidnplayr	738
		739	mov eax, [edx + TCP_header.SequenceNumber]
		740	add eax, ecx
		741	sub eax, [ebx + TCP_SOCKET.RCV_NXT]
		742	sub eax, [ebx + TCP_SOCKET.RCV_WND] ; eax now holds the number of bytes to drop
		743	jle .no_excess_data
		744
6908	ashmew2	745	DEBUGF DEBUG_NETWORK_VERBOSE, "%d bytes beyond right edge of window\n", eax
3545	hidnplayr	746
6476	hidnplayr	747	inc [TCPS_rcvpackafterwin]
		748
3545	hidnplayr	749	cmp eax, ecx
		750	jl .dont_drop_all
6476	hidnplayr	751
		752	add [TCPS_rcvbyteafterwin], ecx
		753
		754	;----------------------------------------------------------------------------------------------------
3545	hidnplayr	755	; If a new connection request is received while in TIME_WAIT, drop the old connection and start over,
		756	; if the sequence numbers are above the previous ones
		757
		758	test [edx + TCP_header.Flags], TH_SYN
		759	jz .no_new_request
6476	hidnplayr	760	cmp [ebx + TCP_SOCKET.t_state], TCPS_TIME_WAIT
3545	hidnplayr	761	jne .no_new_request
		762	; mov edx, [ebx + TCP_SOCKET.RCV_NXT]
		763	; cmp edx, [edx + TCP_header.SequenceNumber]
		764	; add edx, 64000 ; TCP_ISSINCR FIXME
		765	mov eax, ebx
6011	hidnplayr	766	call tcp_close
3545	hidnplayr	767	jmp .findpcb ; FIXME: skip code for unscaling window, ...
		768	.no_new_request:
		769
4339	hidnplayr	770	; If window is closed, we can only take segments at window edge, and have to drop data and PUSH from
3545	hidnplayr	771	; incoming segments. Continue processing, but remember to ACK. Otherwise drop segment and ACK
		772
		773	cmp [ebx + TCP_SOCKET.RCV_WND], 0
		774	jne .drop_after_ack
4339	hidnplayr	775	mov esi, [edx + TCP_header.SequenceNumber]
		776	cmp esi, [ebx + TCP_SOCKET.RCV_NXT]
3545	hidnplayr	777	jne .drop_after_ack
		778
		779	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
6476	hidnplayr	780	inc [TCPS_rcvwinprobe]
3545	hidnplayr	781	.dont_drop_all:
6476	hidnplayr	782	add [TCPS_rcvbyteafterwin], eax
6908	ashmew2	783	DEBUGF DEBUG_NETWORK_VERBOSE, "Trimming %u bytes from the right of the window\n"
6476	hidnplayr	784
		785	; remove data from the right side of window (decrease data length)
		786
		787	sub ecx, eax
4347	hidnplayr	788	and [edx + TCP_header.Flags], not (TH_PUSH or TH_FIN)
3545	hidnplayr	789	.no_excess_data:
		790
6476	hidnplayr	791	;-----------------------------------------------------------------------------------
		792	;
4339	hidnplayr	793	; Record timestamp
6476	hidnplayr	794	;
		795	;-----------------------------------------------------------------------------------
3545	hidnplayr	796
		797	; If last ACK falls within this segments sequence numbers, record its timestamp
6476	hidnplayr	798
4347	hidnplayr	799	test [temp_bits], TCP_BIT_TIMESTAMP
3545	hidnplayr	800	jz .no_timestamp
		801	mov eax, [ebx + TCP_SOCKET.last_ack_sent]
		802	sub eax, [edx + TCP_header.SequenceNumber]
		803	jb .no_timestamp
6476	hidnplayr	804	test [edx + TCP_header.Flags], TH_SYN or TH_FIN ; SYN and FIN occupy one byte
3545	hidnplayr	805	jz @f
		806	dec eax
		807	@@:
		808	sub eax, ecx
		809	jae .no_timestamp
		810
6908	ashmew2	811	DEBUGF DEBUG_NETWORK_VERBOSE, "Recording timestamp\n"
3545	hidnplayr	812
4344	hidnplayr	813	mov eax, [timestamp]
3545	hidnplayr	814	mov [ebx + TCP_SOCKET.ts_recent_age], eax
		815	mov eax, [ebx + TCP_SOCKET.ts_val]
		816	mov [ebx + TCP_SOCKET.ts_recent], eax
		817	.no_timestamp:
		818
6476	hidnplayr	819	;-----------------------------------------------------------------------------------
		820	;
		821	; Process RST flag
		822	;
		823	;-----------------------------------------------------------------------------------
3545	hidnplayr	824
		825	test [edx + TCP_header.Flags], TH_RST
		826	jz .no_rst
		827
6908	ashmew2	828	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Got an RST flag\n"
3545	hidnplayr	829
		830	mov eax, [ebx + TCP_SOCKET.t_state]
		831	shl eax, 2
		832	jmp dword [eax + .rst_sw_list]
		833
6476	hidnplayr	834	;-----------------------------------------------------------------------------------
3545	hidnplayr	835	.rst_sw_list:
		836	dd .no_rst ; TCPS_CLOSED
		837	dd .no_rst ; TCPS_LISTEN
		838	dd .no_rst ; TCPS_SYN_SENT
		839	dd .econnrefused ; TCPS_SYN_RECEIVED
		840	dd .econnreset ; TCPS_ESTABLISHED
		841	dd .econnreset ; TCPS_CLOSE_WAIT
		842	dd .econnreset ; TCPS_FIN_WAIT_1
		843	dd .rst_close ; TCPS_CLOSING
		844	dd .rst_close ; TCPS_LAST_ACK
		845	dd .econnreset ; TCPS_FIN_WAIT_2
6476	hidnplayr	846	dd .rst_close ; TCPS_TIME_WAIT
3545	hidnplayr	847
6476	hidnplayr	848	;-----------------------------------------------------------------------------------
3545	hidnplayr	849	.econnrefused:
6908	ashmew2	850	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Connection refused\n"
3545	hidnplayr	851	mov [ebx + SOCKET.errorcode], ECONNREFUSED
		852	jmp .close
		853
6476	hidnplayr	854	;-----------------------------------------------------------------------------------
3545	hidnplayr	855	.econnreset:
6908	ashmew2	856	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Connection reset\n"
3545	hidnplayr	857	mov [ebx + SOCKET.errorcode], ECONNRESET
		858	.close:
6908	ashmew2	859	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Closing connection\n"
6476	hidnplayr	860	mov [ebx + TCP_SOCKET.t_state], TCPS_CLOSED
		861	inc [TCPS_drops]
3545	hidnplayr	862
6476	hidnplayr	863
6710	clevermous	864	jmp .drop
3545	hidnplayr	865
6476	hidnplayr	866	;-----------------------------------------------------------------------------------
3545	hidnplayr	867	.rst_close:
6908	ashmew2	868	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Closing with reset\n"
6710	clevermous	869	jmp .unlock_and_close
3545	hidnplayr	870
6476	hidnplayr	871	;-----------------------------------------------------------------------------------
3545	hidnplayr	872	.no_rst:
		873
6476	hidnplayr	874	;-----------------------------------------------------------------------------------
		875	;
		876	; Handle SYN-full and ACK-less segments
		877	;
		878	;-----------------------------------------------------------------------------------
3545	hidnplayr	879
6476	hidnplayr	880	; If a SYN is in the window, then this is an error so we send an RST and drop the connection
		881
3545	hidnplayr	882	test [edx + TCP_header.Flags], TH_SYN
		883	jz .not_syn_full
		884
		885	mov eax, ebx
		886	mov ebx, ECONNRESET
6011	hidnplayr	887	call tcp_drop
3545	hidnplayr	888	jmp .drop_with_reset
		889	.not_syn_full:
		890
6476	hidnplayr	891	; If ACK bit is off, we drop the segment and return
3545	hidnplayr	892
		893	test [edx + TCP_header.Flags], TH_ACK
		894	jz .drop
		895
6476	hidnplayr	896	;----------------------------------------------------------------------------------
		897	;
		898	; ACK processing for SYN_RECEIVED state
		899	;
		900	;----------------------------------------------------------------------------------
		901
3545	hidnplayr	902	cmp [ebx + TCP_SOCKET.t_state], TCPS_SYN_RECEIVED
		903	jb .ack_processed ; states: closed, listen, syn_sent
		904	ja .no_syn_rcv ; established, fin_wait_1, fin_wait_2, close_wait, closing, last_ack, time_wait
		905
6908	ashmew2	906	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: state=syn_received\n"
3545	hidnplayr	907
		908	mov eax, [edx + TCP_header.AckNumber]
		909	cmp [ebx + TCP_SOCKET.SND_UNA], eax
		910	ja .drop_with_reset
		911	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		912	ja .drop_with_reset
		913
6476	hidnplayr	914	inc [TCPS_connects]
3545	hidnplayr	915
		916	mov eax, ebx
6011	hidnplayr	917	call socket_is_connected
3545	hidnplayr	918	mov [ebx + TCP_SOCKET.t_state], TCPS_ESTABLISHED
		919
		920	; Do window scaling?
		921
		922	test [ebx + TCP_SOCKET.t_flags], TF_RCVD_SCALE
		923	jz @f
		924	test [ebx + TCP_SOCKET.t_flags], TF_REQ_SCALE
		925	jz @f
		926
6476	hidnplayr	927	push word[ebx + TCP_SOCKET.requested_s_scale] ; Set send and receive scale factors to the received values
		928	pop word[ebx + TCP_SOCKET.SND_SCALE]
3545	hidnplayr	929	@@:
		930
6011	hidnplayr	931	call tcp_reassemble
3545	hidnplayr	932
		933	mov eax, [edx + TCP_header.SequenceNumber]
		934	dec eax
		935	mov [ebx + TCP_SOCKET.SND_WL1], eax
		936	.no_syn_rcv:
		937
6476	hidnplayr	938	;-----------------------------------------------------------------------------------
		939	;
		940	; ACK processing for SYN_RECEIVED state and higher
		941	;
		942	;-----------------------------------------------------------------------------------
		943
3545	hidnplayr	944	;-------------------------
6476	hidnplayr	945	; Check for duplicate ACKs
3545	hidnplayr	946
		947	mov eax, [edx + TCP_header.AckNumber]
		948	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
6476	hidnplayr	949	ja .dup_ack_complete
3545	hidnplayr	950
		951	test ecx, ecx
		952	jnz .reset_dupacks
		953
6476	hidnplayr	954	mov eax, dword[edx + TCP_header.Window]
3545	hidnplayr	955	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		956	jne .reset_dupacks
		957
6476	hidnplayr	958	inc [TCPS_rcvdupack]
6908	ashmew2	959	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Processing duplicate ACK\n"
3545	hidnplayr	960
		961	; If we have outstanding data, other than a window probe, this is a completely duplicate ACK
		962	; (window info didnt change) The ACK is the biggest we've seen and we've seen exactly our rexmt threshold of them,
		963	; assume a packet has been dropped and retransmit it. Kludge snd_nxt & the congestion window so we send only this one packet.
		964
3600	hidnplayr	965	test [ebx + TCP_SOCKET.timer_flags], timer_flag_retransmission
6476	hidnplayr	966	jz .reset_dupacks
3545	hidnplayr	967
		968	mov eax, [edx + TCP_header.AckNumber]
		969	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
6476	hidnplayr	970	jne .reset_dupacks
3545	hidnplayr	971
6476	hidnplayr	972	; Increment dupplicat ACK counter
		973	; If it reaches the threshold, re-transmit the missing segment
3545	hidnplayr	974
		975	inc [ebx + TCP_SOCKET.t_dupacks]
		976	cmp [ebx + TCP_SOCKET.t_dupacks], TCP_re_xmit_thresh
6476	hidnplayr	977	jb .dup_ack_complete
		978	ja .another_lost
3545	hidnplayr	979
6908	ashmew2	980	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Re-transmitting lost segment\n"
6476	hidnplayr	981
3545	hidnplayr	982	push [ebx + TCP_SOCKET.SND_NXT] ; >>>>
		983
		984	mov eax, [ebx + TCP_SOCKET.SND_WND]
		985	cmp eax, [ebx + TCP_SOCKET.SND_CWND]
4296	hidnplayr	986	jbe @f
		987	mov eax, [ebx + TCP_SOCKET.SND_CWND]
		988	@@:
3545	hidnplayr	989	shr eax, 1
		990	push edx
		991	xor edx, edx
		992	div [ebx + TCP_SOCKET.t_maxseg]
		993	cmp eax, 2
		994	ja @f
		995	xor eax, eax
		996	mov al, 2
		997	@@:
		998	mul [ebx + TCP_SOCKET.t_maxseg]
		999	pop edx
		1000	mov [ebx + TCP_SOCKET.SND_SSTHRESH], eax
		1001
3600	hidnplayr	1002	and [ebx + TCP_SOCKET.timer_flags], not timer_flag_retransmission ; turn off retransmission timer
3545	hidnplayr	1003	mov [ebx + TCP_SOCKET.t_rtt], 0
		1004	mov eax, [edx + TCP_header.AckNumber]
		1005	mov [ebx + TCP_SOCKET.SND_NXT], eax
		1006	mov eax, [ebx + TCP_SOCKET.t_maxseg]
		1007	mov [ebx + TCP_SOCKET.SND_CWND], eax
		1008
		1009	; Unlock the socket
6476	hidnplayr	1010
3545	hidnplayr	1011	push ebx
		1012	lea ecx, [ebx + SOCKET.mutex]
		1013	call mutex_unlock
		1014
		1015	; retransmit missing segment
6476	hidnplayr	1016
3545	hidnplayr	1017	mov eax, [esp]
6011	hidnplayr	1018	call tcp_output
3545	hidnplayr	1019
		1020	; Lock the socket again
6476	hidnplayr	1021
3545	hidnplayr	1022	mov ecx, [esp]
		1023	add ecx, SOCKET.mutex
		1024	call mutex_lock
3711	clevermous	1025	pop ebx
3545	hidnplayr	1026
		1027	; Continue processing
6476	hidnplayr	1028
3545	hidnplayr	1029	xor edx, edx
		1030	mov eax, [ebx + TCP_SOCKET.t_maxseg]
		1031	mul [ebx + TCP_SOCKET.t_dupacks]
		1032	add eax, [ebx + TCP_SOCKET.SND_SSTHRESH]
		1033	mov [ebx + TCP_SOCKET.SND_CWND], eax
		1034
		1035	pop eax ; <<<<
		1036	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		1037	jb @f
		1038	mov [ebx + TCP_SOCKET.SND_NXT], eax
		1039	@@:
		1040	jmp .drop
		1041
6476	hidnplayr	1042	.another_lost:
6908	ashmew2	1043	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Increasing congestion window\n"
3545	hidnplayr	1044
		1045	mov eax, [ebx + TCP_SOCKET.t_maxseg]
		1046	add [ebx + TCP_SOCKET.SND_CWND], eax
		1047
		1048	; Unlock the socket
6476	hidnplayr	1049
3545	hidnplayr	1050	push ebx
		1051	lea ecx, [ebx + SOCKET.mutex]
		1052	call mutex_unlock
		1053
6476	hidnplayr	1054	; retransmit missing segment, again
		1055
3545	hidnplayr	1056	mov eax, [esp]
6011	hidnplayr	1057	call tcp_output
3545	hidnplayr	1058
		1059	; Lock the socket again
6476	hidnplayr	1060
3545	hidnplayr	1061	mov ecx, [esp]
		1062	add ecx, SOCKET.mutex
		1063	call mutex_lock
		1064	pop ebx
		1065
6476	hidnplayr	1066	; And drop the incoming segment
		1067
3545	hidnplayr	1068	jmp .drop
		1069
6476	hidnplayr	1070	.reset_dupacks: ; We got a new ACK, reset duplicate ACK counter
		1071	mov [ebx + TCP_SOCKET.t_dupacks], 0
		1072	jmp .ack_processed
3545	hidnplayr	1073
6476	hidnplayr	1074	.dup_ack_complete:
3545	hidnplayr	1075
		1076	;-------------------------------------------------
		1077	; If the congestion window was inflated to account
		1078	; for the other side's cached packets, retract it
		1079
		1080	mov eax, [ebx + TCP_SOCKET.SND_SSTHRESH]
		1081	cmp eax, [ebx + TCP_SOCKET.SND_CWND]
		1082	ja @f
		1083	cmp [ebx + TCP_SOCKET.t_dupacks], TCP_re_xmit_thresh
		1084	jbe @f
		1085	mov [ebx + TCP_SOCKET.SND_CWND], eax
		1086	@@:
		1087
		1088	mov [ebx + TCP_SOCKET.t_dupacks], 0
		1089
		1090	mov eax, [edx + TCP_header.AckNumber]
		1091	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		1092	jbe @f
5442	hidnplayr	1093	inc [TCPS_rcvacktoomuch]
3545	hidnplayr	1094	jmp .drop_after_ack
		1095	@@:
		1096
		1097	mov edi, [edx + TCP_header.AckNumber]
		1098	sub edi, [ebx + TCP_SOCKET.SND_UNA] ; now we got the number of acked bytes in edi
5442	hidnplayr	1099	inc [TCPS_rcvackpack]
		1100	add [TCPS_rcvackbyte], edi
6908	ashmew2	1101	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: acceptable ACK for %u bytes\n", edi
3545	hidnplayr	1102
6476	hidnplayr	1103	;-----------------------------------------------------------------------------------
		1104	;
4347	hidnplayr	1105	; RTT measurements and retransmission timer
6476	hidnplayr	1106	;
		1107	;-----------------------------------------------------------------------------------
3545	hidnplayr	1108
		1109	; If we have a timestamp, update smoothed RTT
		1110
4347	hidnplayr	1111	test [temp_bits], TCP_BIT_TIMESTAMP
3545	hidnplayr	1112	jz .timestamp_not_present
4344	hidnplayr	1113	mov eax, [timestamp]
3545	hidnplayr	1114	sub eax, [ebx + TCP_SOCKET.ts_ecr]
		1115	inc eax
6011	hidnplayr	1116	call tcp_xmit_timer
3545	hidnplayr	1117	jmp .rtt_done_
		1118
		1119	; If no timestamp but transmit timer is running and timed sequence number was acked,
		1120	; update smoothed RTT. Since we now have an RTT measurement, cancel the timer backoff
		1121	; (Phil Karn's retransmit algo)
		1122	; Recompute the initial retransmit timer
		1123
		1124	.timestamp_not_present:
		1125	mov eax, [edx + TCP_header.AckNumber]
		1126	cmp eax, [ebx + TCP_SOCKET.t_rtseq]
		1127	jbe .rtt_done_
		1128	mov eax, [ebx + TCP_SOCKET.t_rtt]
		1129	test eax, eax
		1130	jz .rtt_done_
6011	hidnplayr	1131	call tcp_xmit_timer
3545	hidnplayr	1132	.rtt_done_:
		1133
		1134	; If all outstanding data is acked, stop retransmit timer and remember to restart (more output or persist)
		1135	; If there is more data to be acked, restart retransmit timer, using current (possible backed-off) value.
		1136
		1137	mov eax, [ebx + TCP_SOCKET.SND_MAX]
		1138	cmp eax, [edx + TCP_header.AckNumber]
		1139	jne .more_data
3600	hidnplayr	1140	and [ebx + TCP_SOCKET.timer_flags], not timer_flag_retransmission
4347	hidnplayr	1141	or [temp_bits], TCP_BIT_NEEDOUTPUT
3545	hidnplayr	1142	jmp .no_restart
		1143	.more_data:
3600	hidnplayr	1144	test [ebx + TCP_SOCKET.timer_flags], timer_flag_persist
		1145	jnz .no_restart
3545	hidnplayr	1146
		1147	mov eax, [ebx + TCP_SOCKET.t_rxtcur]
		1148	mov [ebx + TCP_SOCKET.timer_retransmission], eax
3600	hidnplayr	1149	or [ebx + TCP_SOCKET.timer_flags], timer_flag_retransmission
3545	hidnplayr	1150	.no_restart:
		1151
6476	hidnplayr	1152	;-----------------------------------------------------------------------------------
		1153	;
3545	hidnplayr	1154	; Open congestion window in response to ACKs
6476	hidnplayr	1155	;
		1156	;-----------------------------------------------------------------------------------
3545	hidnplayr	1157
6476	hidnplayr	1158	; If the window gives us less then sstresh packets in flight, open exponentially.
		1159	; Otherwise, open lineary
		1160
3545	hidnplayr	1161	mov esi, [ebx + TCP_SOCKET.SND_CWND]
		1162	mov eax, [ebx + TCP_SOCKET.t_maxseg]
		1163	cmp esi, [ebx + TCP_SOCKET.SND_SSTHRESH]
		1164	jbe @f
		1165	push edx
		1166	push eax
6476	hidnplayr	1167	mul eax ; t_maxseg*t_maxseg
		1168	div esi ; t_maxseg*t_maxseg/snd_cwnd
		1169	pop edx ; t_maxseg
		1170	shr edx, 3 ; t_maxseg/8
		1171	add eax, edx ; t_maxseg*t_maxseg/snd_cwnd + t_maxseg/8
3545	hidnplayr	1172	pop edx
		1173	@@:
		1174	add esi, eax
		1175
		1176	push ecx
		1177	mov cl, [ebx + TCP_SOCKET.SND_SCALE]
		1178	mov eax, TCP_max_win
		1179	shl eax, cl
		1180	pop ecx
		1181
		1182	cmp esi, eax
4296	hidnplayr	1183	jbe @f
		1184	mov esi, eax
		1185	@@:
3545	hidnplayr	1186	mov [ebx + TCP_SOCKET.SND_CWND], esi
		1187
6476	hidnplayr	1188	;-----------------------------------------------------------------------------------
		1189	;
3545	hidnplayr	1190	; Remove acknowledged data from send buffer
6476	hidnplayr	1191	;
		1192	;-----------------------------------------------------------------------------------
3545	hidnplayr	1193
6476	hidnplayr	1194	; If the number of bytes acknowledged exceeds the number of bytes on the send buffer,
		1195	; snd_wnd is decremented by the number of bytes in the send buffer and TCP knows
		1196	; that its FIN has been ACKed. (FIN occupies 1 byte in the sequence number space)
		1197
3545	hidnplayr	1198	cmp edi, [ebx + STREAM_SOCKET.snd.size]
6476	hidnplayr	1199	jbe .no_fin_ack
3545	hidnplayr	1200
6476	hidnplayr	1201	; Drop all data in output buffer
		1202
3545	hidnplayr	1203	push ecx edx ebx
		1204	mov ecx, [ebx + STREAM_SOCKET.snd.size]
6476	hidnplayr	1205	sub [ebx + TCP_SOCKET.SND_WND], ecx
3545	hidnplayr	1206	lea eax, [ebx + STREAM_SOCKET.snd]
6011	hidnplayr	1207	call socket_ring_free
3545	hidnplayr	1208	pop ebx edx ecx
		1209
6908	ashmew2	1210	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: our FIN is acked\n"
5133	hidnplayr	1211	or [temp_bits], TCP_BIT_FIN_IS_ACKED
6476	hidnplayr	1212	jmp .ack_complete
		1213	.no_fin_ack:
3545	hidnplayr	1214
6476	hidnplayr	1215	; Drop acknowledged data
3545	hidnplayr	1216
		1217	push ecx edx ebx
		1218	mov ecx, edi
		1219	lea eax, [ebx + STREAM_SOCKET.snd]
6011	hidnplayr	1220	call socket_ring_free
3545	hidnplayr	1221	pop ebx
		1222	sub [ebx + TCP_SOCKET.SND_WND], ecx
		1223	pop edx ecx
6476	hidnplayr	1224	.ack_complete:
3545	hidnplayr	1225
6476	hidnplayr	1226	;-----------------------------------------------------------------------------------
		1227	;
3545	hidnplayr	1228	; Wake up process waiting on send buffer
6476	hidnplayr	1229	;
		1230	;-----------------------------------------------------------------------------------
3545	hidnplayr	1231
		1232	mov eax, ebx
6011	hidnplayr	1233	call socket_notify
3545	hidnplayr	1234
		1235	; Update TCPS
6476	hidnplayr	1236
3545	hidnplayr	1237	mov eax, [edx + TCP_header.AckNumber]
		1238	mov [ebx + TCP_SOCKET.SND_UNA], eax
		1239	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		1240	jb @f
		1241	mov [ebx + TCP_SOCKET.SND_NXT], eax
		1242	@@:
		1243
6476	hidnplayr	1244	;-----------------------------------------------------------------------------------
		1245	;
		1246	; State specific ACK handeling
		1247	;
		1248	;-----------------------------------------------------------------------------------
3545	hidnplayr	1249
		1250	mov eax, [ebx + TCP_SOCKET.t_state]
6476	hidnplayr	1251	jmp dword[.ack_sw_list+eax*4]
3545	hidnplayr	1252
6476	hidnplayr	1253	.ack_sw_list:
3545	hidnplayr	1254	dd .ack_processed ; TCPS_CLOSED
		1255	dd .ack_processed ; TCPS_LISTEN
		1256	dd .ack_processed ; TCPS_SYN_SENT
		1257	dd .ack_processed ; TCPS_SYN_RECEIVED
		1258	dd .ack_processed ; TCPS_ESTABLISHED
		1259	dd .ack_processed ; TCPS_CLOSE_WAIT
		1260	dd .ack_fw1 ; TCPS_FIN_WAIT_1
		1261	dd .ack_c ; TCPS_CLOSING
		1262	dd .ack_la ; TCPS_LAST_ACK
		1263	dd .ack_processed ; TCPS_FIN_WAIT_2
		1264	dd .ack_tw ; TCPS_TIMED_WAIT
		1265
6476	hidnplayr	1266	;-----------------------------------------------------------------------------------
		1267	.ack_fw1:
		1268	; If our FIN is now acked, enter FIN_WAIT_2
3545	hidnplayr	1269
5133	hidnplayr	1270	test [temp_bits], TCP_BIT_FIN_IS_ACKED
		1271	jz .ack_processed
3545	hidnplayr	1272
6476	hidnplayr	1273	; If we can't receive any more data, then closing user can proceed.
		1274	; Starting the timer is contrary to the specification, but if we dont get a FIN,
		1275	; we'll hang forever.
		1276
3545	hidnplayr	1277	test [ebx + SOCKET.state], SS_CANTRCVMORE
		1278	jnz @f
		1279	mov eax, ebx
6011	hidnplayr	1280	call socket_is_disconnected
3545	hidnplayr	1281	mov [ebx + TCP_SOCKET.timer_timed_wait], TCP_time_max_idle
3600	hidnplayr	1282	or [ebx + TCP_SOCKET.timer_flags], timer_flag_wait
3545	hidnplayr	1283	@@:
		1284	mov [ebx + TCP_SOCKET.t_state], TCPS_FIN_WAIT_2
		1285	jmp .ack_processed
		1286
6476	hidnplayr	1287	;-----------------------------------------------------------------------------------
3545	hidnplayr	1288	.ack_c:
6476	hidnplayr	1289	; Enter the TIME_WAIT state if our FIN is acked in CLOSED state.
		1290
5133	hidnplayr	1291	test [temp_bits], TCP_BIT_FIN_IS_ACKED
		1292	jz .ack_processed
3545	hidnplayr	1293
6476	hidnplayr	1294	mov [ebx + TCP_SOCKET.t_state], TCPS_TIME_WAIT
3545	hidnplayr	1295	mov eax, ebx
6011	hidnplayr	1296	call tcp_cancel_timers
3545	hidnplayr	1297	mov [ebx + TCP_SOCKET.timer_timed_wait], 2 * TCP_time_MSL
3600	hidnplayr	1298	or [ebx + TCP_SOCKET.timer_flags], timer_flag_wait
3545	hidnplayr	1299	mov eax, ebx
6011	hidnplayr	1300	call socket_is_disconnected
3545	hidnplayr	1301	jmp .ack_processed
		1302
6476	hidnplayr	1303	;-----------------------------------------------------------------------------------
3545	hidnplayr	1304	.ack_la:
6476	hidnplayr	1305	; In LAST_ACK state, we may still be waiting for data to drain and/or to be acked.
		1306	; If our FIN is acked however, enter CLOSED state and return.
		1307
5133	hidnplayr	1308	test [temp_bits], TCP_BIT_FIN_IS_ACKED
		1309	jz .ack_processed
3545	hidnplayr	1310
6710	clevermous	1311	.unlock_and_close:
3652	hidnplayr	1312	push ebx
		1313	lea ecx, [ebx + SOCKET.mutex]
		1314	call mutex_unlock
6476	hidnplayr	1315	pop eax
3652	hidnplayr	1316
6011	hidnplayr	1317	call tcp_close
4366	hidnplayr	1318	jmp .drop_no_socket
3545	hidnplayr	1319
6476	hidnplayr	1320	;-----------------------------------------------------------------------------------
3545	hidnplayr	1321	.ack_tw:
6476	hidnplayr	1322	; In TIME_WAIT state the only thing that should arrive is a retransmission of the remote FIN.
		1323	; Acknowledge it and restart the FINACK timer
		1324
		1325	mov [ebx + TCP_SOCKET.timer_timed_wait], 2*TCP_time_MSL
		1326	or [ebx + TCP_SOCKET.timer_flags], timer_flag_2msl
3545	hidnplayr	1327	jmp .drop_after_ack
		1328
6476	hidnplayr	1329	;-----------------------------------------------------------------------------------
		1330	;
		1331	; Initiation of Passive Open?
		1332	;
		1333	;-----------------------------------------------------------------------------------
3545	hidnplayr	1334
6476	hidnplayr	1335	.state_listen:
6908	ashmew2	1336	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: state=listen\n"
3545	hidnplayr	1337
		1338	test [edx + TCP_header.Flags], TH_RST
		1339	jnz .drop
		1340
		1341	test [edx + TCP_header.Flags], TH_ACK
		1342	jnz .drop_with_reset
		1343
		1344	test [edx + TCP_header.Flags], TH_SYN
		1345	jz .drop
		1346
6476	hidnplayr	1347	inc [TCPS_accepts]
5442	hidnplayr	1348
3545	hidnplayr	1349	;;; TODO: check if it's a broadcast or multicast, and drop if so
		1350
6476	hidnplayr	1351	;-------------------------------------------
		1352	; Processing of SYN received in LISTEN state
		1353
5842	hidnplayr	1354	push [edi + IPv4_header.SourceAddress]
3545	hidnplayr	1355	pop [ebx + IP_SOCKET.RemoteIP]
		1356
		1357	push [edx + TCP_header.SourcePort]
		1358	pop [ebx + TCP_SOCKET.RemotePort]
		1359
		1360	push [edx + TCP_header.SequenceNumber]
		1361	pop [ebx + TCP_SOCKET.IRS]
		1362
		1363	mov eax, [TCP_sequence_num]
6476	hidnplayr	1364	add [TCP_sequence_num], TCP_ISSINCR / 2
3545	hidnplayr	1365	mov [ebx + TCP_SOCKET.ISS], eax
		1366	mov [ebx + TCP_SOCKET.SND_NXT], eax
		1367
6011	hidnplayr	1368	tcp_sendseqinit ebx
		1369	tcp_rcvseqinit ebx
3545	hidnplayr	1370
		1371	mov [ebx + TCP_SOCKET.t_state], TCPS_SYN_RECEIVED
4347	hidnplayr	1372	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
3545	hidnplayr	1373	mov [ebx + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval ;;;; macro
3600	hidnplayr	1374	or [ebx + TCP_SOCKET.timer_flags], timer_flag_keepalive
3545	hidnplayr	1375
		1376	lea eax, [ebx + STREAM_SOCKET.snd]
6011	hidnplayr	1377	call socket_ring_create
5155	hidnplayr	1378	test eax, eax
		1379	jz .drop
3545	hidnplayr	1380
		1381	lea eax, [ebx + STREAM_SOCKET.rcv]
6011	hidnplayr	1382	call socket_ring_create
5155	hidnplayr	1383	test eax, eax
		1384	jz .drop
3545	hidnplayr	1385
4347	hidnplayr	1386	and [temp_bits], not TCP_BIT_DROPSOCKET
3545	hidnplayr	1387
3674	hidnplayr	1388	pusha
		1389	mov eax, ebx
6011	hidnplayr	1390	call socket_notify
3674	hidnplayr	1391	popa
3545	hidnplayr	1392
5133	hidnplayr	1393	jmp .trim
3545	hidnplayr	1394
6476	hidnplayr	1395	;-----------------------------------------------------------------------------------
		1396	;
		1397	; Completion of active open?
		1398	;
		1399	;-----------------------------------------------------------------------------------
3545	hidnplayr	1400
6476	hidnplayr	1401	.state_syn_sent:
6908	ashmew2	1402	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: state=syn_sent\n"
3545	hidnplayr	1403
		1404	test [edx + TCP_header.Flags], TH_ACK
		1405	jz @f
		1406
		1407	mov eax, [edx + TCP_header.AckNumber]
		1408	cmp eax, [ebx + TCP_SOCKET.ISS]
		1409	jbe .drop_with_reset
		1410
		1411	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		1412	ja .drop_with_reset
		1413	@@:
		1414
		1415	test [edx + TCP_header.Flags], TH_RST
		1416	jz @f
		1417
		1418	test [edx + TCP_header.Flags], TH_ACK
		1419	jz .drop
		1420
		1421	mov eax, ebx
		1422	mov ebx, ECONNREFUSED
6011	hidnplayr	1423	call tcp_drop
3545	hidnplayr	1424	jmp .drop
		1425	@@:
		1426
6476	hidnplayr	1427	;-----------------------------------------------------------------------------------
		1428	;
		1429	; Process received SYN in response to an active open
		1430	;
		1431	;-----------------------------------------------------------------------------------
		1432
3545	hidnplayr	1433	test [edx + TCP_header.Flags], TH_SYN
		1434	jz .drop
		1435
		1436	test [edx + TCP_header.Flags], TH_ACK
6476	hidnplayr	1437	jz @f
3545	hidnplayr	1438
		1439	mov eax, [edx + TCP_header.AckNumber]
		1440	mov [ebx + TCP_SOCKET.SND_UNA], eax
		1441	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		1442	jbe @f
		1443	mov [ebx + TCP_SOCKET.SND_NXT], eax
		1444
3600	hidnplayr	1445	and [ebx + TCP_SOCKET.timer_flags], not timer_flag_retransmission ; disable retransmission timer
6476	hidnplayr	1446	@@:
3545	hidnplayr	1447
		1448	push [edx + TCP_header.SequenceNumber]
		1449	pop [ebx + TCP_SOCKET.IRS]
		1450
6011	hidnplayr	1451	tcp_rcvseqinit ebx
3545	hidnplayr	1452
		1453	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
		1454
		1455	mov eax, [ebx + TCP_SOCKET.SND_UNA]
		1456	cmp eax, [ebx + TCP_SOCKET.ISS]
		1457	jbe .simultaneous_open
		1458
		1459	test [edx + TCP_header.Flags], TH_ACK
		1460	jz .simultaneous_open
		1461
6908	ashmew2	1462	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: active open\n"
3545	hidnplayr	1463
6476	hidnplayr	1464	inc [TCPS_connects]
3545	hidnplayr	1465
		1466	; set socket state to connected
6476	hidnplayr	1467
3674	hidnplayr	1468	push eax
		1469	mov eax, ebx
6011	hidnplayr	1470	call socket_is_connected
3674	hidnplayr	1471	pop eax
3545	hidnplayr	1472	mov [ebx + TCP_SOCKET.t_state], TCPS_ESTABLISHED
		1473
		1474	; Do window scaling on this connection ?
6476	hidnplayr	1475
3545	hidnplayr	1476	mov eax, [ebx + TCP_SOCKET.t_flags]
		1477	and eax, TF_REQ_SCALE or TF_RCVD_SCALE
		1478	cmp eax, TF_REQ_SCALE or TF_RCVD_SCALE
		1479	jne .no_scaling
		1480
6011	hidnplayr	1481	mov ax, word[ebx + TCP_SOCKET.requested_s_scale]
		1482	mov word[ebx + TCP_SOCKET.SND_SCALE], ax
3545	hidnplayr	1483	.no_scaling:
		1484
		1485	;;; TODO: reassemble packets queue
		1486
6476	hidnplayr	1487	; If we didnt have time to re-transmit the SYN,
		1488	; Use its rtt as our initial srtt & rtt var.
		1489
3545	hidnplayr	1490	mov eax, [ebx + TCP_SOCKET.t_rtt]
		1491	test eax, eax
5133	hidnplayr	1492	je .trim
6011	hidnplayr	1493	call tcp_xmit_timer
5133	hidnplayr	1494	jmp .trim
3545	hidnplayr	1495
6476	hidnplayr	1496	;-----------------------------------------------------------------------------------
		1497	;
		1498	; Simultaneous open (We have received a SYN but no ACK)
		1499	;
		1500	;-----------------------------------------------------------------------------------
		1501
3545	hidnplayr	1502	.simultaneous_open:
6908	ashmew2	1503	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: simultaneous open\n"
3545	hidnplayr	1504	mov [ebx + TCP_SOCKET.t_state], TCPS_SYN_RECEIVED
		1505
6476	hidnplayr	1506	;-----------------------------------------------------------------------------------
		1507	;
3545	hidnplayr	1508	; Common processing for receipt of SYN
6476	hidnplayr	1509	;
		1510	;-----------------------------------------------------------------------------------
3545	hidnplayr	1511
5133	hidnplayr	1512	.trim:
6476	hidnplayr	1513	; Advance sequence number to correspond to first data byte.
		1514	; If data, trim to stay within window, dropping FIN if necessary
		1515
3545	hidnplayr	1516	inc [edx + TCP_header.SequenceNumber]
		1517
4339	hidnplayr	1518	; Drop any received data that doesnt fit in the receive window.
6476	hidnplayr	1519
4339	hidnplayr	1520	cmp ecx, [ebx + TCP_SOCKET.RCV_WND]
		1521	jbe .dont_trim
3545	hidnplayr	1522
6908	ashmew2	1523	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: received data does not fit in window, trimming %u bytes\n", eax
6476	hidnplayr	1524	inc [TCPS_rcvpackafterwin]
		1525	sub ecx, [ebx + TCP_SOCKET.RCV_WND]
		1526	add [TCPS_rcvbyteafterwin], ecx
		1527
		1528	and [edx + TCP_header.Flags], not (TH_FIN)
4339	hidnplayr	1529	mov ecx, [ebx + TCP_SOCKET.RCV_WND]
		1530
		1531	.dont_trim:
3545	hidnplayr	1532	mov eax, [edx + TCP_header.SequenceNumber]
		1533	mov [ebx + TCP_SOCKET.RCV_UP], eax
		1534	dec eax
		1535	mov [ebx + TCP_SOCKET.SND_WL1], eax
		1536
6476	hidnplayr	1537	;-----------------------------------------------------------------------------------
		1538	;
		1539	; Update window information (step 6 in RFC793)
		1540	;
		1541	;-----------------------------------------------------------------------------------
		1542
3545	hidnplayr	1543	.ack_processed:
6908	ashmew2	1544	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: ACK processed\n"
3545	hidnplayr	1545
6476	hidnplayr	1546	; dont look at window if no ACK
3545	hidnplayr	1547
		1548	test [edx + TCP_header.Flags], TH_ACK
		1549	jz .no_window_update
		1550
6476	hidnplayr	1551	; Does the segment contain new data?
		1552
3545	hidnplayr	1553	mov eax, [ebx + TCP_SOCKET.SND_WL1]
		1554	cmp eax, [edx + TCP_header.SequenceNumber]
		1555	jb .update_window
		1556	ja @f
		1557
6476	hidnplayr	1558	; No new data but a new ACK ?
		1559
3545	hidnplayr	1560	mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1561	cmp eax, [edx + TCP_header.AckNumber]
		1562	jb .update_window
		1563	@@:
		1564
6476	hidnplayr	1565	; No new data or ACK but advertised window is larger then current window?
		1566
		1567	mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1568	cmp eax, [edx + TCP_header.AckNumber]
		1569	jne .no_window_update
		1570
		1571	mov eax, dword[edx + TCP_header.Window]
3545	hidnplayr	1572	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		1573	jbe .no_window_update
		1574
6476	hidnplayr	1575
		1576	; Keep track of pure window updates
3545	hidnplayr	1577	.update_window:
6476	hidnplayr	1578	test ecx, ecx
		1579	jnz @f
		1580	mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1581	cmp eax, [edx + TCP_header.AckNumber]
		1582	jne @f
		1583	mov eax, dword[edx + TCP_header.Window]
		1584	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		1585	jbe @f
		1586	inc [TCPS_rcvwinupd]
		1587	@@:
3545	hidnplayr	1588
6476	hidnplayr	1589	mov eax, dword[edx + TCP_header.Window]
		1590	mov [ebx + TCP_SOCKET.SND_WND], eax
3545	hidnplayr	1591	cmp eax, [ebx + TCP_SOCKET.max_sndwnd]
		1592	jbe @f
		1593	mov [ebx + TCP_SOCKET.max_sndwnd], eax
		1594	@@:
		1595
6908	ashmew2	1596	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Updating window to %u\n", eax
3545	hidnplayr	1597
		1598	push [edx + TCP_header.SequenceNumber]
		1599	pop [ebx + TCP_SOCKET.SND_WL1]
		1600
		1601	push [edx + TCP_header.AckNumber]
		1602	pop [ebx + TCP_SOCKET.SND_WL2]
		1603
4347	hidnplayr	1604	or [temp_bits], TCP_BIT_NEEDOUTPUT
3545	hidnplayr	1605	.no_window_update:
		1606
6476	hidnplayr	1607	;-----------------------------------------------------------------------------------
		1608	;
		1609	; Process URG flag
		1610	;
		1611	;-----------------------------------------------------------------------------------
3545	hidnplayr	1612
		1613	test [edx + TCP_header.Flags], TH_URG
		1614	jz .not_urgent
		1615
		1616	cmp [edx + TCP_header.UrgentPointer], 0
		1617	jz .not_urgent
		1618
6476	hidnplayr	1619	cmp [ebx + TCP_SOCKET.t_state], TCPS_TIME_WAIT
3545	hidnplayr	1620	je .not_urgent
		1621
		1622	; Ignore bogus urgent offsets
		1623
		1624	movzx eax, [edx + TCP_header.UrgentPointer]
		1625	add eax, [ebx + STREAM_SOCKET.rcv.size]
6413	hidnplayr	1626	cmp eax, SOCKET_BUFFER_SIZE
3545	hidnplayr	1627	jbe .not_urgent
		1628
		1629	mov [edx + TCP_header.UrgentPointer], 0
		1630	and [edx + TCP_header.Flags], not (TH_URG)
		1631	jmp .do_data
		1632
		1633	.not_urgent:
		1634
		1635	; processing of received urgent pointer
		1636
		1637	;;; TODO (1051-1093)
		1638
6476	hidnplayr	1639	;-----------------------------------------------------------------------------------
		1640	;
		1641	; Process the data
		1642	;
		1643	;-----------------------------------------------------------------------------------
3545	hidnplayr	1644
		1645	.do_data:
6476	hidnplayr	1646	cmp [ebx + TCP_SOCKET.t_state], TCPS_TIME_WAIT
3545	hidnplayr	1647	jae .final_processing
		1648
		1649	test [edx + TCP_header.Flags], TH_FIN
		1650	jnz @f
		1651
		1652	test ecx, ecx
3756	hidnplayr	1653	jz .final_processing
3545	hidnplayr	1654	@@:
		1655
		1656	; The segment is in order?
6476	hidnplayr	1657
3545	hidnplayr	1658	mov eax, [edx + TCP_header.SequenceNumber]
		1659	cmp eax, [ebx + TCP_SOCKET.RCV_NXT]
		1660	jne .out_of_order
		1661
		1662	; The reassembly queue is empty?
6476	hidnplayr	1663
3545	hidnplayr	1664	cmp [ebx + TCP_SOCKET.seg_next], 0
		1665	jne .out_of_order
		1666
		1667	; The connection is established?
6476	hidnplayr	1668
3545	hidnplayr	1669	cmp [ebx + TCP_SOCKET.t_state], TCPS_ESTABLISHED
		1670	jne .out_of_order
		1671
		1672	; Ok, lets do this.. Set delayed ACK flag and copy data into socket buffer
6476	hidnplayr	1673
3545	hidnplayr	1674	or [ebx + TCP_SOCKET.t_flags], TF_DELACK
		1675
		1676	pusha
4339	hidnplayr	1677	mov esi, [dataoffset]
3545	hidnplayr	1678	add esi, edx
		1679	lea eax, [ebx + STREAM_SOCKET.rcv]
6011	hidnplayr	1680	call socket_ring_write ; Add the data to the socket buffer
3545	hidnplayr	1681	add [ebx + TCP_SOCKET.RCV_NXT], ecx ; Update sequence number with number of bytes we have copied
		1682	popa
		1683
		1684	; Wake up the sleeping process
6476	hidnplayr	1685
3545	hidnplayr	1686	mov eax, ebx
6011	hidnplayr	1687	call socket_notify
3545	hidnplayr	1688
		1689	jmp .data_done
		1690
		1691	.out_of_order:
6908	ashmew2	1692	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP data is out of order!\nSequencenumber is %u, we expected %u.\n", \
4339	hidnplayr	1693	[edx + TCP_header.SequenceNumber], [ebx + TCP_SOCKET.RCV_NXT]
3545	hidnplayr	1694
		1695	; Uh-oh, some data is out of order, lets call TCP reassemble for help
		1696
6915	hidnplayr	1697	call tcp_reassemble ;;; TODO!
3545	hidnplayr	1698
4339	hidnplayr	1699	; Generate ACK immediately, to let the other end know that a segment was received out of order,
		1700	; and to tell it what sequence number is expected. This aids the fast-retransmit algorithm.
6476	hidnplayr	1701
3545	hidnplayr	1702	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
6915	hidnplayr	1703
		1704	jmp .final_processing ;;; HACK because of unimplemented reassembly queue!
3545	hidnplayr	1705	.data_done:
		1706
6476	hidnplayr	1707	;-----------------------------------------------------------------------------------
		1708	;
		1709	; Process FIN
		1710	;
		1711	;-----------------------------------------------------------------------------------
3545	hidnplayr	1712
		1713	test [edx + TCP_header.Flags], TH_FIN
		1714	jz .final_processing
		1715
6908	ashmew2	1716	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Processing FIN\n"
3545	hidnplayr	1717
6476	hidnplayr	1718	cmp [ebx + TCP_SOCKET.t_state], TCPS_TIME_WAIT
3545	hidnplayr	1719	jae .not_first_fin
		1720
6908	ashmew2	1721	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: First FIN for this connection\n"
3545	hidnplayr	1722
		1723	mov eax, ebx
6011	hidnplayr	1724	call socket_cant_recv_more
3545	hidnplayr	1725
4347	hidnplayr	1726	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
3545	hidnplayr	1727	inc [ebx + TCP_SOCKET.RCV_NXT]
		1728
		1729	.not_first_fin:
		1730	mov eax, [ebx + TCP_SOCKET.t_state]
6476	hidnplayr	1731	jmp dword[.fin_sw_list+eax*4]
3545	hidnplayr	1732
6476	hidnplayr	1733	.fin_sw_list:
3545	hidnplayr	1734	dd .final_processing ; TCPS_CLOSED
		1735	dd .final_processing ; TCPS_LISTEN
		1736	dd .final_processing ; TCPS_SYN_SENT
		1737	dd .fin_syn_est ; TCPS_SYN_RECEIVED
		1738	dd .fin_syn_est ; TCPS_ESTABLISHED
		1739	dd .final_processing ; TCPS_CLOSE_WAIT
		1740	dd .fin_wait1 ; TCPS_FIN_WAIT_1
		1741	dd .final_processing ; TCPS_CLOSING
		1742	dd .final_processing ; TCPS_LAST_ACK
		1743	dd .fin_wait2 ; TCPS_FIN_WAIT_2
		1744	dd .fin_timed ; TCPS_TIMED_WAIT
		1745
6476	hidnplayr	1746	;-----------------------------------------------------------------------------------
3545	hidnplayr	1747	.fin_syn_est:
6476	hidnplayr	1748	; In SYN_RECEIVED and ESTABLISHED state, enter the CLOSE_WAIT state
		1749
3545	hidnplayr	1750	mov [ebx + TCP_SOCKET.t_state], TCPS_CLOSE_WAIT
		1751	jmp .final_processing
		1752
6476	hidnplayr	1753	;-----------------------------------------------------------------------------------
3545	hidnplayr	1754	.fin_wait1:
6476	hidnplayr	1755	; From FIN_WAIT_1 state, enter CLOSING state (our FIN has not been ACKed)
		1756
3545	hidnplayr	1757	mov [ebx + TCP_SOCKET.t_state], TCPS_CLOSING
		1758	jmp .final_processing
		1759
6476	hidnplayr	1760	;-----------------------------------------------------------------------------------
3545	hidnplayr	1761	.fin_wait2:
6476	hidnplayr	1762	; From FIN_WAIT_2 state, enter TIME_WAIT state and start the timer
		1763
		1764	mov [ebx + TCP_SOCKET.t_state], TCPS_TIME_WAIT
3545	hidnplayr	1765	mov eax, ebx
6011	hidnplayr	1766	call tcp_cancel_timers
		1767	call socket_is_disconnected
3545	hidnplayr	1768
6476	hidnplayr	1769	;-----------------------------------------------------------------------------------
3545	hidnplayr	1770	.fin_timed:
6476	hidnplayr	1771	; (re)start the 2 MSL timer
3545	hidnplayr	1772	mov [ebx + TCP_SOCKET.timer_timed_wait], 2 * TCP_time_MSL
3600	hidnplayr	1773	or [ebx + TCP_SOCKET.timer_flags], timer_flag_wait
3545	hidnplayr	1774
6476	hidnplayr	1775	;-----------------------------------------------------------------------------------
		1776	;
		1777	; Finally, drop the segment
		1778	;
		1779	;-----------------------------------------------------------------------------------
3545	hidnplayr	1780
4347	hidnplayr	1781	.final_processing:
6908	ashmew2	1782	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Final processing\n"
4347	hidnplayr	1783
		1784	push ebx
		1785	lea ecx, [ebx + SOCKET.mutex]
		1786	call mutex_unlock
		1787	pop eax
		1788
		1789	test [temp_bits], TCP_BIT_NEEDOUTPUT
		1790	jnz .need_output
		1791
		1792	test [eax + TCP_SOCKET.t_flags], TF_ACKNOW
5133	hidnplayr	1793	jz .done
6908	ashmew2	1794	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: ACK now!\n"
4347	hidnplayr	1795
		1796	.need_output:
6908	ashmew2	1797	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: need output\n"
6011	hidnplayr	1798	call tcp_output
4347	hidnplayr	1799
5133	hidnplayr	1800	.done:
6908	ashmew2	1801	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: dumping\n"
4347	hidnplayr	1802
6011	hidnplayr	1803	call net_buff_free
4347	hidnplayr	1804	jmp .loop
		1805
6476	hidnplayr	1806	;-----------------------------------------------------------------------------------
		1807	;
		1808	; Drop segment, reply with an RST segment when needed
		1809	;
		1810	;-----------------------------------------------------------------------------------
4347	hidnplayr	1811
6476	hidnplayr	1812	;-----------------------------------------------------------------------------------
3545	hidnplayr	1813	.drop_after_ack:
6908	ashmew2	1814	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Drop after ACK\n"
3545	hidnplayr	1815
		1816	push edx ebx
		1817	lea ecx, [ebx + SOCKET.mutex]
		1818	call mutex_unlock
		1819	pop eax edx
		1820
		1821	test [edx + TCP_header.Flags], TH_RST
5133	hidnplayr	1822	jnz .done
3545	hidnplayr	1823
		1824	or [eax + TCP_SOCKET.t_flags], TF_ACKNOW
		1825	jmp .need_output
		1826
6476	hidnplayr	1827	;-----------------------------------------------------------------------------------
3545	hidnplayr	1828	.drop_with_reset:
6908	ashmew2	1829	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Drop with reset\n"
3545	hidnplayr	1830
		1831	push ebx edx
		1832	lea ecx, [ebx + SOCKET.mutex]
		1833	call mutex_unlock
		1834	pop edx ebx
		1835
		1836	test [edx + TCP_header.Flags], TH_RST
5133	hidnplayr	1837	jnz .done
3545	hidnplayr	1838
6011	hidnplayr	1839	; TODO: if its a multicast/broadcast, also drop
3545	hidnplayr	1840
		1841	test [edx + TCP_header.Flags], TH_ACK
		1842	jnz .respond_ack
		1843
		1844	test [edx + TCP_header.Flags], TH_SYN
		1845	jnz .respond_syn
5133	hidnplayr	1846	jmp .done
3545	hidnplayr	1847
		1848	.respond_ack:
		1849	push ebx
		1850	mov cl, TH_RST
6011	hidnplayr	1851	call tcp_respond
3545	hidnplayr	1852	pop ebx
		1853	jmp .destroy_new_socket
		1854
		1855	.respond_syn:
		1856	push ebx
		1857	mov cl, TH_RST + TH_ACK
6011	hidnplayr	1858	call tcp_respond
3545	hidnplayr	1859	pop ebx
		1860	jmp .destroy_new_socket
		1861
5133	hidnplayr	1862	;-----------------------------------------
		1863	; The connection has no associated socket
		1864
3647	hidnplayr	1865	.no_socket:
		1866	pusha
		1867	mov ecx, socket_mutex
		1868	call mutex_unlock
		1869	popa
		1870
3545	hidnplayr	1871	.respond_seg_reset:
		1872	test [edx + TCP_header.Flags], TH_RST
		1873	jnz .drop_no_socket
		1874
6011	hidnplayr	1875	; TODO: if its a multicast/broadcast, also drop
3545	hidnplayr	1876
		1877	test [edx + TCP_header.Flags], TH_ACK
		1878	jnz .respond_seg_ack
		1879
		1880	test [edx + TCP_header.Flags], TH_SYN
		1881	jnz .respond_seg_syn
		1882
		1883	jmp .drop_no_socket
		1884
		1885	.respond_seg_ack:
		1886	mov cl, TH_RST
6910	hidnplayr	1887	mov ebx, [device]
6011	hidnplayr	1888	call tcp_respond_segment
3545	hidnplayr	1889	jmp .drop_no_socket
		1890
		1891	.respond_seg_syn:
		1892	mov cl, TH_RST + TH_ACK
6910	hidnplayr	1893	mov ebx, [device]
6011	hidnplayr	1894	call tcp_respond_segment
3545	hidnplayr	1895	jmp .drop_no_socket
		1896
5133	hidnplayr	1897	;------------------------------------------------
		1898	; Unlock socket mutex and prepare to drop segment
3545	hidnplayr	1899
		1900	.drop:
6908	ashmew2	1901	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Dropping segment\n"
3545	hidnplayr	1902
		1903	pusha
		1904	lea ecx, [ebx + SOCKET.mutex]
		1905	call mutex_unlock
		1906	popa
		1907
5133	hidnplayr	1908	;--------------------------------------------
		1909	; Destroy the newly created socket if needed
		1910
3545	hidnplayr	1911	.destroy_new_socket:
4347	hidnplayr	1912	test [temp_bits], TCP_BIT_DROPSOCKET
3545	hidnplayr	1913	jz .drop_no_socket
		1914
		1915	mov eax, ebx
6011	hidnplayr	1916	call socket_free
3545	hidnplayr	1917
5133	hidnplayr	1918	;------------------
		1919	; Drop the segment
		1920
3545	hidnplayr	1921	.drop_no_socket:
6908	ashmew2	1922	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Drop (no socket)\n"
3545	hidnplayr	1923
6011	hidnplayr	1924	call net_buff_free
3545	hidnplayr	1925	jmp .loop
4339	hidnplayr	1926
		1927	endp

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(root)/kernel/trunk/network/tcp_input.inc – Rev 6915