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

Rev	Author	Line No.	Line
3545	hidnplayr	1	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
		2	;; ;;
10051	ace_dent	3	;; Copyright (C) KolibriOS team 2004-2024. 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
		17
6476	hidnplayr	18	TCP_BIT_NEEDOUTPUT = 1 shl 0
		19	TCP_BIT_TIMESTAMP = 1 shl 1
		20	TCP_BIT_DROPSOCKET = 1 shl 2
		21	TCP_BIT_FIN_IS_ACKED = 1 shl 3
		22
5976	hidnplayr	23	;-----------------------------------------------------------------;
		24	; ;
		25	; TCP_input: Add a segment to the incoming TCP queue. ;
		26	; ;
		27	; IN: [esp] = ptr to buffer ;
		28	; ebx = ptr to device struct ;
		29	; ecx = TCP segment size ;
		30	; edx = ptr to IPv4 header ;
		31	; esi = ptr to TCP segment ;
		32	; edi = interface number*4 ;
		33	; ;
		34	; OUT: / ;
		35	; ;
		36	;-----------------------------------------------------------------;
3545	hidnplayr	37	align 4
6011	hidnplayr	38	tcp_input:
6908	ashmew2	39
3545	hidnplayr	40	; record the current time
5522	hidnplayr	41	push [timer_ticks] ; in 1/100 seconds
5842	hidnplayr	42	push ebx ecx esi edx ; mind the order (see TCP_queue_entry struct)
3545	hidnplayr	43	mov esi, esp
		44
5842	hidnplayr	45	push edi
3545	hidnplayr	46	add_to_queue TCP_queue, TCP_QUEUE_SIZE, sizeof.TCP_queue_entry, .fail
5842	hidnplayr	47	pop edi
3545	hidnplayr	48	add esp, sizeof.TCP_queue_entry
		49
3644	hidnplayr	50	inc [TCP_segments_rx + edi]
		51
3545	hidnplayr	52	xor edx, edx
		53	mov eax, [TCP_input_event]
		54	mov ebx, [eax + EVENT.id]
		55	xor esi, esi
		56	call raise_event
		57
		58	ret
		59
		60	.fail:
5842	hidnplayr	61	pop edi
3556	hidnplayr	62	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP incoming queue is full, discarding packet!\n"
3545	hidnplayr	63
6011	hidnplayr	64	call net_ptr_to_num4
3644	hidnplayr	65	inc [TCP_segments_missed + edi]
3545	hidnplayr	66
5841	hidnplayr	67	add esp, sizeof.TCP_queue_entry - 4
6011	hidnplayr	68	call net_buff_free
3545	hidnplayr	69	ret
		70
		71
6476	hidnplayr	72	;-----------------------------------------------------------------;
		73	; ;
		74	; TCP_process_input: Process segments from the incoming TCP queue.;
		75	; ;
		76	; IN: / ;
		77	; OUT: / ;
		78	; ;
		79	;-----------------------------------------------------------------;
3545	hidnplayr	80	align 4
6011	hidnplayr	81	proc tcp_process_input
3545	hidnplayr	82
4339	hidnplayr	83	locals
		84	dataoffset dd ?
4344	hidnplayr	85	timestamp dd ?
4347	hidnplayr	86	temp_bits db ?
6910	hidnplayr	87	device dd ?
4339	hidnplayr	88	endl
		89
3545	hidnplayr	90	xor esi, esi
		91	mov ecx, MANUAL_DESTROY
		92	call create_event
		93	mov [TCP_input_event], eax
		94
		95	.wait:
		96	mov eax, [TCP_input_event]
		97	mov ebx, [eax + EVENT.id]
		98	call wait_event
		99
		100	.loop:
		101	get_from_queue TCP_queue, TCP_QUEUE_SIZE, sizeof.TCP_queue_entry, .wait
		102
		103	push [esi + TCP_queue_entry.timestamp]
4344	hidnplayr	104	pop [timestamp]
3545	hidnplayr	105	push [esi + TCP_queue_entry.buffer_ptr]
		106
		107	mov ebx, [esi + TCP_queue_entry.device_ptr]
6910	hidnplayr	108	mov [device], ebx
3545	hidnplayr	109	mov ecx, [esi + TCP_queue_entry.segment_size]
6910	hidnplayr	110	mov edi, [esi + TCP_queue_entry.ip_ptr] ; ptr to ipv4 header
3545	hidnplayr	111	mov esi, [esi + TCP_queue_entry.segment_ptr] ; change esi last
		112
6908	ashmew2	113	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: size=%u time=%d\n", ecx, [timer_ticks]
3545	hidnplayr	114
		115	mov edx, esi
		116
6476	hidnplayr	117	; Verify the checksum (if not already done by hw)
3545	hidnplayr	118
4388	hidnplayr	119	test [ebx + NET_DEVICE.hwacc], NET_HWACC_TCP_IPv4_IN
		120	jnz .checksum_ok
3545	hidnplayr	121
		122	push ecx esi
		123	pushw [esi + TCP_header.Checksum]
		124	mov [esi + TCP_header.Checksum], 0
6011	hidnplayr	125	tcp_checksum (edi+IPv4_header.SourceAddress), (edi+IPv4_header.DestinationAddress)
5842	hidnplayr	126	pop cx ; previous checksum
3545	hidnplayr	127	cmp cx, dx
		128	pop edx ecx
		129	jne .drop_no_socket
		130	.checksum_ok:
		131
		132	; Verify the data offset
6476	hidnplayr	133
4339	hidnplayr	134	movzx eax, [edx + TCP_header.DataOffset]
		135	and al, 0xf0 ; Calculate TCP segment header size (throwing away unused reserved bits in TCP header)
		136	shr al, 2
		137	cmp al, sizeof.TCP_header ; Now see if it's at least the size of a standard TCP header
		138	jb .drop_no_socket ; If not, drop the packet
		139	mov [dataoffset], eax
3545	hidnplayr	140
		141	sub ecx, eax ; substract TCP header size from total segment size
		142	jb .drop_no_socket ; If total segment size is less then the advertised header size, drop packet
6908	ashmew2	143	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: %u bytes of data\n", ecx
3545	hidnplayr	144
		145	;-------------------------------------------
		146	; Convert Big-endian values to little endian
		147
		148	ntohd [edx + TCP_header.SequenceNumber]
		149	ntohd [edx + TCP_header.AckNumber]
		150
		151	ntohw [edx + TCP_header.Window]
		152	ntohw [edx + TCP_header.UrgentPointer]
		153
6476	hidnplayr	154	;-----------------------------------------------------------------------------------
		155	;
3545	hidnplayr	156	; Find the socket pointer
6476	hidnplayr	157	;
		158	;-----------------------------------------------------------------------------------
3545	hidnplayr	159
		160	; IP Packet TCP Destination Port = local Port
		161	; (IP Packet SenderAddress = Remote IP) OR (Remote IP = 0)
		162	; (IP Packet TCP Source Port = remote Port) OR (remote Port = 0)
		163
		164	.findpcb:
3647	hidnplayr	165	pusha
		166	mov ecx, socket_mutex
		167	call mutex_lock
		168	popa
		169
3545	hidnplayr	170	mov ebx, net_sockets
		171	mov si, [edx + TCP_header.DestinationPort]
		172
		173	.socket_loop:
		174	mov ebx, [ebx + SOCKET.NextPtr]
		175	or ebx, ebx
3647	hidnplayr	176	jz .no_socket ;respond_seg_reset
3545	hidnplayr	177
		178	cmp [ebx + SOCKET.Domain], AF_INET4
		179	jne .socket_loop
		180
		181	cmp [ebx + SOCKET.Protocol], IP_PROTO_TCP
		182	jne .socket_loop
		183
		184	cmp [ebx + TCP_SOCKET.LocalPort], si
		185	jne .socket_loop
		186
		187	mov eax, [ebx + IP_SOCKET.RemoteIP]
5842	hidnplayr	188	cmp eax, [edi + IPv4_header.SourceAddress]
3545	hidnplayr	189	je @f
		190	test eax, eax
		191	jnz .socket_loop
		192	@@:
		193
		194	mov ax, [ebx + TCP_SOCKET.RemotePort]
		195	cmp [edx + TCP_header.SourcePort], ax
		196	je .found_socket
		197	test ax, ax
		198	jnz .socket_loop
		199	.found_socket: ; ebx now contains the socketpointer
3647	hidnplayr	200	pusha
		201	mov ecx, socket_mutex
		202	call mutex_unlock
		203	popa
		204
6908	ashmew2	205	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	206
		207	;----------------------------
		208	; Check if socket isnt closed
		209
		210	cmp [ebx + TCP_SOCKET.t_state], TCPS_CLOSED
		211	je .drop_no_socket
		212
		213	;----------------
		214	; Lock the socket
		215
		216	pusha
		217	lea ecx, [ebx + SOCKET.mutex]
		218	call mutex_lock
		219	popa
		220
6908	ashmew2	221	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: socket locked\n"
3545	hidnplayr	222
		223	;---------------------------
		224	; disable all temporary bits
		225
4347	hidnplayr	226	mov [temp_bits], 0
3545	hidnplayr	227
		228	;---------------------------------------
		229	; unscale the window into a 32 bit value
		230
		231	movzx eax, [edx + TCP_header.Window]
		232	push ecx
		233	mov cl, [ebx + TCP_SOCKET.SND_SCALE]
		234	shl eax, cl
6476	hidnplayr	235	mov dword[edx + TCP_header.Window], eax ; word after window is checksum, we dont need checksum anymore
3545	hidnplayr	236	pop ecx
		237
6476	hidnplayr	238	;-----------------------------------------------------------------------------------
		239	;
		240	; Accept incoming connections
		241	;
		242	;-----------------------------------------------------------------------------------
3545	hidnplayr	243
		244	test [ebx + SOCKET.options], SO_ACCEPTCON
		245	jz .no_accept
		246
6908	ashmew2	247	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Accepting new connection\n"
3545	hidnplayr	248
6476	hidnplayr	249	; Unlock current socket
		250
3545	hidnplayr	251	pusha
		252	lea ecx, [ebx + SOCKET.mutex]
		253	call mutex_unlock
		254	popa
		255
6476	hidnplayr	256	; Fork it
		257
5842	hidnplayr	258	push ecx edx esi edi
6011	hidnplayr	259	call socket_fork
3545	hidnplayr	260	pop edi esi edx ecx
		261
		262	test eax, eax
		263	jz .drop_no_socket
		264
6476	hidnplayr	265	; Success! Use the new socket from now on (it is already locked)
		266
3545	hidnplayr	267	mov ebx, eax
		268
4347	hidnplayr	269	mov [temp_bits], TCP_BIT_DROPSOCKET
3545	hidnplayr	270
5842	hidnplayr	271	push [edi + IPv4_header.DestinationAddress]
3545	hidnplayr	272	pop [ebx + IP_SOCKET.LocalIP]
		273
		274	push [edx + TCP_header.DestinationPort]
		275	pop [ebx + TCP_SOCKET.LocalPort]
		276
		277	mov [ebx + TCP_SOCKET.t_state], TCPS_LISTEN
		278	.no_accept:
		279
		280
		281	;-------------------------------------
		282	; Reset idle timer and keepalive timer
		283
		284	mov [ebx + TCP_SOCKET.t_idle], 0
		285	mov [ebx + TCP_SOCKET.timer_keepalive], TCP_time_keep_idle
3600	hidnplayr	286	or [ebx + TCP_SOCKET.timer_flags], timer_flag_keepalive
3545	hidnplayr	287
6476	hidnplayr	288	;-----------------------------------------------------------------------------------
		289	;
3545	hidnplayr	290	; Process TCP options
6476	hidnplayr	291	;
		292	;-----------------------------------------------------------------------------------
3545	hidnplayr	293
4339	hidnplayr	294	;;; FIXME: for LISTEN, options should be called after we determined route, we need it for MSS
		295	;;; cmp [ebx + TCP_SOCKET.t_state], TCPS_LISTEN ; no options when in listen state
		296	;;; jz .not_uni_xfer ; also no header prediction
		297
3545	hidnplayr	298	push ecx
		299
4339	hidnplayr	300	mov ecx, [dataoffset]
6476	hidnplayr	301	cmp ecx, sizeof.TCP_header ; Does header contain any options?
3545	hidnplayr	302	je .no_options
		303
6908	ashmew2	304	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Segment has options\n"
3545	hidnplayr	305
		306	add ecx, edx
		307	lea esi, [edx + sizeof.TCP_header]
		308
		309	.opt_loop:
		310	cmp esi, ecx ; are we scanning outside of header?
		311	jae .no_options
		312	lodsb
		313	cmp al, TCP_OPT_EOL ; end of option list?
		314	je .no_options
		315	cmp al, TCP_OPT_NOP
		316	je .opt_loop
		317	cmp al, TCP_OPT_MAXSEG
		318	je .opt_maxseg
		319	cmp al, TCP_OPT_WINDOW
		320	je .opt_window
		321	cmp al, TCP_OPT_SACK_PERMIT
		322	je .opt_sack_permit
		323	; cmp al, TCP_OPT_SACK
		324	; je .opt_sack
		325	cmp al, TCP_OPT_TIMESTAMP
		326	je .opt_timestamp
6908	ashmew2	327	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: unknown option:%u\n", al
3545	hidnplayr	328	jmp .no_options ; If we reach here, some unknown options were received, skip them all!
		329
		330	.opt_maxseg:
		331	lodsb
		332	cmp al, 4
		333	jne .no_options ; error occured, ignore all options!
		334
		335	test [edx + TCP_header.Flags], TH_SYN
		336	jz @f
		337
4339	hidnplayr	338	xor eax, eax
3545	hidnplayr	339	lodsw
		340	rol ax, 8
6908	ashmew2	341	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Maxseg=%u\n", eax
6011	hidnplayr	342	call tcp_mss
3545	hidnplayr	343	@@:
		344	jmp .opt_loop
		345
		346
		347	.opt_window:
		348	lodsb
		349	cmp al, 3
		350	jne .no_options
		351
		352	test [edx + TCP_header.Flags], TH_SYN
		353	jz @f
		354
6908	ashmew2	355	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Got window scale option\n"
3545	hidnplayr	356	or [ebx + TCP_SOCKET.t_flags], TF_RCVD_SCALE
		357
		358	lodsb
		359	mov [ebx + TCP_SOCKET.SND_SCALE], al
		360	;;;;; TODO
		361
		362	@@:
		363	jmp .opt_loop
		364
		365
		366	.opt_sack_permit:
		367	lodsb
		368	cmp al, 2
		369	jne .no_options
		370
		371	test [edx + TCP_header.Flags], TH_SYN
		372	jz @f
		373
6908	ashmew2	374	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Selective Acknowledgement permitted\n"
3545	hidnplayr	375	or [ebx + TCP_SOCKET.t_flags], TF_SACK_PERMIT
		376
		377	@@:
		378	jmp .opt_loop
		379
		380
		381	.opt_timestamp:
		382	lodsb
		383	cmp al, 10 ; length must be 10
		384	jne .no_options
		385
6908	ashmew2	386	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Got timestamp option\n"
3545	hidnplayr	387
		388	test [edx + TCP_header.Flags], TH_SYN
		389	jz @f
		390	or [ebx + TCP_SOCKET.t_flags], TF_RCVD_TSTMP
		391	@@:
		392
		393	lodsd
4344	hidnplayr	394	bswap eax
3545	hidnplayr	395	mov [ebx + TCP_SOCKET.ts_val], eax
		396	lodsd ; timestamp echo reply
		397	mov [ebx + TCP_SOCKET.ts_ecr], eax
4347	hidnplayr	398	or [temp_bits], TCP_BIT_TIMESTAMP
3545	hidnplayr	399
		400	; Since we have a timestamp, lets do the paws test right away!
		401
		402	test [edx + TCP_header.Flags], TH_RST
		403	jnz .no_paws
		404
		405	mov eax, [ebx + TCP_SOCKET.ts_recent]
		406	test eax, eax
		407	jz .no_paws
		408	cmp eax, [ebx + TCP_SOCKET.ts_val]
4344	hidnplayr	409	jbe .no_paws
3545	hidnplayr	410
6908	ashmew2	411	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: PAWS: detected an old segment\n"
3545	hidnplayr	412
4344	hidnplayr	413	mov eax, [timestamp]
3545	hidnplayr	414	sub eax, [ebx + TCP_SOCKET.ts_recent_age]
		415
		416	pop ecx
		417	cmp eax, TCP_PAWS_IDLE
5442	hidnplayr	418	jle .paws_drop
3545	hidnplayr	419	push ecx
		420	mov [ebx + TCP_SOCKET.ts_recent], 0 ; timestamp was invalid, fix it.
		421	.no_paws:
		422	jmp .opt_loop
		423
5442	hidnplayr	424	.paws_drop:
6476	hidnplayr	425	inc [TCPS_rcvduppack]
5442	hidnplayr	426	add [TCPS_rcvdupbyte], ecx
		427	inc [TCPS_pawsdrop]
		428	jmp .drop_after_ack
		429
3545	hidnplayr	430	.no_options:
		431
		432	pop ecx
		433
6476	hidnplayr	434	;-----------------------------------------------------------------------------------
		435	;
		436	; Header prediction
		437	;
		438	;-----------------------------------------------------------------------------------
3545	hidnplayr	439
6476	hidnplayr	440	; According to Van Jacobson, there are two common cases for an uni-directional data transfer.
3545	hidnplayr	441	;
		442	; General rule: the packets has no control flags, is in-sequence,
		443	; window width didnt change and we're not retransmitting.
		444	;
		445	; Second rules:
		446	; - If the length is 0 and the ACK moved forward, we're the sender side of the transfer.
		447	; In this case we'll free the ACK'ed data and notify higher levels that we have free space in buffer
		448	;
		449	; - If the length is not 0 and the ACK didn't move, we're the receiver side of the transfer.
		450	; If the packets are in order (data queue is empty), add the data to the socket buffer and request a delayed ACK
		451
		452	cmp [ebx + TCP_SOCKET.t_state], TCPS_ESTABLISHED
		453	jnz .not_uni_xfer
		454
		455	test [edx + TCP_header.Flags], TH_SYN + TH_FIN + TH_RST + TH_URG
		456	jnz .not_uni_xfer
		457
		458	test [edx + TCP_header.Flags], TH_ACK
		459	jz .not_uni_xfer
		460
		461	mov eax, [edx + TCP_header.SequenceNumber]
		462	cmp eax, [ebx + TCP_SOCKET.RCV_NXT]
		463	jne .not_uni_xfer
		464
6476	hidnplayr	465	mov eax, dword[edx + TCP_header.Window]
3545	hidnplayr	466	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		467	jne .not_uni_xfer
		468
		469	mov eax, [ebx + TCP_SOCKET.SND_NXT]
		470	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		471	jne .not_uni_xfer
		472
		473	;---------------------------------------
		474	; check if we are sender in the uni-xfer
		475
		476	; If the following 4 conditions are all true, this segment is a pure ACK.
		477	;
		478	; - The segment contains no data.
6476	hidnplayr	479
3545	hidnplayr	480	test ecx, ecx
		481	jnz .not_sender
		482
		483	; - The congestion window is greater than or equal to the current send window.
		484	; 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	485
3545	hidnplayr	486	mov eax, [ebx + TCP_SOCKET.SND_CWND]
		487	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		488	jb .not_uni_xfer
		489
		490	; - The acknowledgment field in the segment is less than or equal to the maximum sequence number sent.
6476	hidnplayr	491
3545	hidnplayr	492	mov eax, [edx + TCP_header.AckNumber]
		493	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		494	ja .not_uni_xfer
		495
		496	; - The acknowledgment field in the segment is greater than the largest unacknowledged sequence number.
6476	hidnplayr	497
3545	hidnplayr	498	sub eax, [ebx + TCP_SOCKET.SND_UNA]
		499	jbe .not_uni_xfer
		500
6908	ashmew2	501	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Header prediction: we are sender\n"
3545	hidnplayr	502
		503	;---------------------------------
		504	; Packet is a pure ACK, process it
		505
6476	hidnplayr	506	inc [TCPS_predack]
		507
		508	inc [TCPS_rcvackpack]
		509	add [TCPS_rcvackbyte], eax
		510
3545	hidnplayr	511	; Delete acknowledged bytes from send buffer
6476	hidnplayr	512
3545	hidnplayr	513	pusha
		514	mov ecx, eax
		515	lea eax, [ebx + STREAM_SOCKET.snd]
6011	hidnplayr	516	call socket_ring_free
3545	hidnplayr	517	popa
		518
		519	; Update RTT estimators
		520
4347	hidnplayr	521	test [temp_bits], TCP_BIT_TIMESTAMP
3545	hidnplayr	522	jz .no_timestamp_rtt
4344	hidnplayr	523	mov eax, [timestamp]
3545	hidnplayr	524	sub eax, [ebx + TCP_SOCKET.ts_ecr]
		525	inc eax
6011	hidnplayr	526	call tcp_xmit_timer
3545	hidnplayr	527	jmp .rtt_done
5976	hidnplayr	528	.no_timestamp_rtt:
3545	hidnplayr	529
		530	cmp [ebx + TCP_SOCKET.t_rtt], 0
		531	je .rtt_done
		532	mov eax, [edx + TCP_header.AckNumber]
		533	cmp eax, [ebx + TCP_SOCKET.t_rtseq]
		534	jbe .rtt_done
		535	mov eax, [ebx + TCP_SOCKET.t_rtt]
6011	hidnplayr	536	call tcp_xmit_timer
3545	hidnplayr	537	.rtt_done:
		538
		539	; update window pointers
6476	hidnplayr	540
3545	hidnplayr	541	mov eax, [edx + TCP_header.AckNumber]
		542	mov [ebx + TCP_SOCKET.SND_UNA], eax
		543
		544	; Stop retransmit timer
6476	hidnplayr	545
3600	hidnplayr	546	and [ebx + TCP_SOCKET.timer_flags], not timer_flag_retransmission
3545	hidnplayr	547
		548	; Unlock the socket
6476	hidnplayr	549
3545	hidnplayr	550	pusha
		551	lea ecx, [ebx + SOCKET.mutex]
		552	call mutex_unlock
		553	popa
		554
		555	; Awaken waiting processes
6476	hidnplayr	556
3545	hidnplayr	557	mov eax, ebx
6011	hidnplayr	558	call socket_notify
3545	hidnplayr	559
		560	; Generate more output
6476	hidnplayr	561
6011	hidnplayr	562	call tcp_output
3545	hidnplayr	563
		564	jmp .drop_no_socket
		565
		566	;-------------------------------------------------
		567	; maybe we are the receiver in the uni-xfer then..
		568
		569	.not_sender:
6476	hidnplayr	570
3545	hidnplayr	571	; - The amount of data in the segment is greater than 0 (data count is in ecx)
6476	hidnplayr	572	; - The acknowledgment field equals the largest unacknowledged sequence number. This means no data is acknowledged by this segment.
3545	hidnplayr	573
		574	mov eax, [edx + TCP_header.AckNumber]
		575	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
		576	jne .not_uni_xfer
		577
5133	hidnplayr	578	; - The reassembly list of out-of-order segments for the connection is empty.
6476	hidnplayr	579
5133	hidnplayr	580	cmp [ebx + TCP_SOCKET.seg_next], 0
		581	jne .not_uni_xfer
3545	hidnplayr	582
		583	; Complete processing of received data
		584
6908	ashmew2	585	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Header prediction: we are receiving %u bytes\n", ecx
3545	hidnplayr	586
4339	hidnplayr	587	mov esi, [dataoffset]
3545	hidnplayr	588	add esi, edx
		589	lea eax, [ebx + STREAM_SOCKET.rcv]
6011	hidnplayr	590	call socket_ring_write ; Add the data to the socket buffer
4344	hidnplayr	591	add [ebx + TCP_SOCKET.RCV_NXT], ecx ; Update sequence number with number of bytes we have copied
3545	hidnplayr	592
		593	mov eax, ebx
6011	hidnplayr	594	call socket_notify
3545	hidnplayr	595
		596	or [ebx + TCP_SOCKET.t_flags], TF_DELACK ; Set delayed ack flag
		597
		598	jmp .drop
		599
		600
6476	hidnplayr	601	;-----------------------------------------------------------------------------------
		602	;
		603	; TCP segment processing, the slow way
		604	;
		605	;-----------------------------------------------------------------------------------
		606
3545	hidnplayr	607	.not_uni_xfer:
6908	ashmew2	608	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Header prediction failed\n"
3545	hidnplayr	609
		610	; Calculate receive window size
6476	hidnplayr	611
3545	hidnplayr	612	push edx
6413	hidnplayr	613	mov eax, SOCKET_BUFFER_SIZE
3545	hidnplayr	614	sub eax, [ebx + STREAM_SOCKET.rcv.size]
6908	ashmew2	615	DEBUGF DEBUG_NETWORK_VERBOSE, "Space in receive buffer=%d\n", eax
3545	hidnplayr	616	mov edx, [ebx + TCP_SOCKET.RCV_ADV]
		617	sub edx, [ebx + TCP_SOCKET.RCV_NXT]
6908	ashmew2	618	DEBUGF DEBUG_NETWORK_VERBOSE, "Current advertised window=%d\n", edx
3545	hidnplayr	619	cmp eax, edx
		620	jg @f
		621	mov eax, edx
		622	@@:
6908	ashmew2	623	DEBUGF DEBUG_NETWORK_VERBOSE, "Receive window size=%d\n", eax
3545	hidnplayr	624	mov [ebx + TCP_SOCKET.RCV_WND], eax
		625	pop edx
		626
		627	; If we are in listen or syn_sent state, go to that specific code right away
		628
		629	cmp [ebx + TCP_SOCKET.t_state], TCPS_LISTEN
6476	hidnplayr	630	je .state_listen
3545	hidnplayr	631
		632	cmp [ebx + TCP_SOCKET.t_state], TCPS_SYN_SENT
6476	hidnplayr	633	je .state_syn_sent
3545	hidnplayr	634
6476	hidnplayr	635	;-----------------------------------------------------------------------------------
		636	;
		637	; Trim any data not in window
		638	;
		639	;-----------------------------------------------------------------------------------
3545	hidnplayr	640
6476	hidnplayr	641	;-------------------------------------------------
		642	; Check for duplicate data at beginning of segment
3545	hidnplayr	643
4339	hidnplayr	644	; Calculate number of bytes we need to drop
6476	hidnplayr	645
3545	hidnplayr	646	mov eax, [ebx + TCP_SOCKET.RCV_NXT]
		647	sub eax, [edx + TCP_header.SequenceNumber]
		648	jle .no_duplicate
		649
6908	ashmew2	650	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: %u bytes duplicate data!\n", eax
3545	hidnplayr	651
6476	hidnplayr	652	; Check for duplicate SYN
		653
3545	hidnplayr	654	test [edx + TCP_header.Flags], TH_SYN
		655	jz .no_dup_syn
		656
6908	ashmew2	657	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: got duplicate syn\n"
3545	hidnplayr	658
		659	and [edx + TCP_header.Flags], not (TH_SYN)
		660	inc [edx + TCP_header.SequenceNumber]
		661
		662	cmp [edx + TCP_header.UrgentPointer], 1
		663	jbe @f
		664	dec [edx + TCP_header.UrgentPointer]
		665	jmp .dup_syn
		666	@@:
		667	and [edx + TCP_header.Flags], not (TH_URG)
		668	.dup_syn:
		669	dec eax
		670	.no_dup_syn:
		671
6476	hidnplayr	672	;-----------------------------------
		673	; Check for entire duplicate segment
		674
3545	hidnplayr	675	cmp eax, ecx ; eax holds number of bytes to drop, ecx is data size
6476	hidnplayr	676	jb .no_complete_dup
3545	hidnplayr	677	jnz @f
		678	test [edx + TCP_header.Flags], TH_FIN
6476	hidnplayr	679	jnz .no_complete_dup
3545	hidnplayr	680	@@:
		681
		682	; Any valid FIN must be to the left of the window.
		683	; At this point the FIN must be out of sequence or a duplicate, drop it
6476	hidnplayr	684
3545	hidnplayr	685	and [edx + TCP_header.Flags], not TH_FIN
		686
6476	hidnplayr	687	; send an ACK to resynchronize and drop any data.
3545	hidnplayr	688	; But keep on processing for RST or ACK
6476	hidnplayr	689
3545	hidnplayr	690	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
		691	mov eax, ecx
		692
6476	hidnplayr	693	inc [TCPS_rcvduppack]
		694	add [TCPS_rcvdupbyte], eax
		695	jmp .dup_processed
		696	.no_complete_dup:
5442	hidnplayr	697	inc [TCPS_rcvpartduppack]
6476	hidnplayr	698	add [TCPS_rcvpartdupbyte], eax
		699	.dup_processed:
5442	hidnplayr	700
3545	hidnplayr	701	;-----------------------------------------------
		702	; Remove duplicate data and update urgent offset
		703
6908	ashmew2	704	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: trimming duplicate data\n"
4339	hidnplayr	705
		706	; Trim data from left side of window
6476	hidnplayr	707
4339	hidnplayr	708	add [dataoffset], eax
3545	hidnplayr	709	add [edx + TCP_header.SequenceNumber], eax
		710	sub ecx, eax
		711
		712	sub [edx + TCP_header.UrgentPointer], ax
		713	jg @f
		714	and [edx + TCP_header.Flags], not (TH_URG)
		715	mov [edx + TCP_header.UrgentPointer], 0
		716	@@:
6476	hidnplayr	717	.no_duplicate:
3545	hidnplayr	718
		719	;--------------------------------------------------
4339	hidnplayr	720	; Handle data that arrives after process terminates
3545	hidnplayr	721
4339	hidnplayr	722	cmp [ebx + SOCKET.PID], 0 ;;; TODO: use socket flags instead??
3545	hidnplayr	723	jne .not_terminated
		724	cmp [ebx + TCP_SOCKET.t_state], TCPS_CLOSE_WAIT
		725	jbe .not_terminated
		726	test ecx, ecx
		727	jz .not_terminated
		728
		729	mov eax, ebx
6011	hidnplayr	730	call tcp_close
5442	hidnplayr	731	inc [TCPS_rcvafterclose]
3545	hidnplayr	732	jmp .respond_seg_reset
6476	hidnplayr	733	.not_terminated:
3545	hidnplayr	734
		735	;----------------------------------------
4339	hidnplayr	736	; Remove data beyond right edge of window
3545	hidnplayr	737
		738	mov eax, [edx + TCP_header.SequenceNumber]
		739	add eax, ecx
		740	sub eax, [ebx + TCP_SOCKET.RCV_NXT]
		741	sub eax, [ebx + TCP_SOCKET.RCV_WND] ; eax now holds the number of bytes to drop
		742	jle .no_excess_data
		743
6908	ashmew2	744	DEBUGF DEBUG_NETWORK_VERBOSE, "%d bytes beyond right edge of window\n", eax
3545	hidnplayr	745
6476	hidnplayr	746	inc [TCPS_rcvpackafterwin]
		747
3545	hidnplayr	748	cmp eax, ecx
		749	jl .dont_drop_all
6476	hidnplayr	750
		751	add [TCPS_rcvbyteafterwin], ecx
		752
		753	;----------------------------------------------------------------------------------------------------
3545	hidnplayr	754	; If a new connection request is received while in TIME_WAIT, drop the old connection and start over,
		755	; if the sequence numbers are above the previous ones
		756
		757	test [edx + TCP_header.Flags], TH_SYN
		758	jz .no_new_request
6476	hidnplayr	759	cmp [ebx + TCP_SOCKET.t_state], TCPS_TIME_WAIT
3545	hidnplayr	760	jne .no_new_request
		761	; mov edx, [ebx + TCP_SOCKET.RCV_NXT]
		762	; cmp edx, [edx + TCP_header.SequenceNumber]
		763	; add edx, 64000 ; TCP_ISSINCR FIXME
		764	mov eax, ebx
6011	hidnplayr	765	call tcp_close
3545	hidnplayr	766	jmp .findpcb ; FIXME: skip code for unscaling window, ...
		767	.no_new_request:
		768
4339	hidnplayr	769	; If window is closed, we can only take segments at window edge, and have to drop data and PUSH from
3545	hidnplayr	770	; incoming segments. Continue processing, but remember to ACK. Otherwise drop segment and ACK
		771
		772	cmp [ebx + TCP_SOCKET.RCV_WND], 0
		773	jne .drop_after_ack
4339	hidnplayr	774	mov esi, [edx + TCP_header.SequenceNumber]
		775	cmp esi, [ebx + TCP_SOCKET.RCV_NXT]
3545	hidnplayr	776	jne .drop_after_ack
		777
		778	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
6476	hidnplayr	779	inc [TCPS_rcvwinprobe]
3545	hidnplayr	780	.dont_drop_all:
6476	hidnplayr	781	add [TCPS_rcvbyteafterwin], eax
6908	ashmew2	782	DEBUGF DEBUG_NETWORK_VERBOSE, "Trimming %u bytes from the right of the window\n"
6476	hidnplayr	783
		784	; remove data from the right side of window (decrease data length)
		785
		786	sub ecx, eax
4347	hidnplayr	787	and [edx + TCP_header.Flags], not (TH_PUSH or TH_FIN)
3545	hidnplayr	788	.no_excess_data:
		789
6476	hidnplayr	790	;-----------------------------------------------------------------------------------
		791	;
4339	hidnplayr	792	; Record timestamp
6476	hidnplayr	793	;
		794	;-----------------------------------------------------------------------------------
3545	hidnplayr	795
		796	; If last ACK falls within this segments sequence numbers, record its timestamp
6476	hidnplayr	797
4347	hidnplayr	798	test [temp_bits], TCP_BIT_TIMESTAMP
3545	hidnplayr	799	jz .no_timestamp
		800	mov eax, [ebx + TCP_SOCKET.last_ack_sent]
		801	sub eax, [edx + TCP_header.SequenceNumber]
		802	jb .no_timestamp
6476	hidnplayr	803	test [edx + TCP_header.Flags], TH_SYN or TH_FIN ; SYN and FIN occupy one byte
3545	hidnplayr	804	jz @f
		805	dec eax
		806	@@:
		807	sub eax, ecx
		808	jae .no_timestamp
		809
6908	ashmew2	810	DEBUGF DEBUG_NETWORK_VERBOSE, "Recording timestamp\n"
3545	hidnplayr	811
4344	hidnplayr	812	mov eax, [timestamp]
3545	hidnplayr	813	mov [ebx + TCP_SOCKET.ts_recent_age], eax
		814	mov eax, [ebx + TCP_SOCKET.ts_val]
		815	mov [ebx + TCP_SOCKET.ts_recent], eax
		816	.no_timestamp:
		817
6476	hidnplayr	818	;-----------------------------------------------------------------------------------
		819	;
		820	; Process RST flag
		821	;
		822	;-----------------------------------------------------------------------------------
3545	hidnplayr	823
		824	test [edx + TCP_header.Flags], TH_RST
		825	jz .no_rst
		826
6908	ashmew2	827	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Got an RST flag\n"
3545	hidnplayr	828
		829	mov eax, [ebx + TCP_SOCKET.t_state]
		830	shl eax, 2
		831	jmp dword [eax + .rst_sw_list]
		832
6476	hidnplayr	833	;-----------------------------------------------------------------------------------
3545	hidnplayr	834	.rst_sw_list:
		835	dd .no_rst ; TCPS_CLOSED
		836	dd .no_rst ; TCPS_LISTEN
		837	dd .no_rst ; TCPS_SYN_SENT
		838	dd .econnrefused ; TCPS_SYN_RECEIVED
		839	dd .econnreset ; TCPS_ESTABLISHED
		840	dd .econnreset ; TCPS_CLOSE_WAIT
		841	dd .econnreset ; TCPS_FIN_WAIT_1
		842	dd .rst_close ; TCPS_CLOSING
		843	dd .rst_close ; TCPS_LAST_ACK
		844	dd .econnreset ; TCPS_FIN_WAIT_2
6476	hidnplayr	845	dd .rst_close ; TCPS_TIME_WAIT
3545	hidnplayr	846
6476	hidnplayr	847	;-----------------------------------------------------------------------------------
3545	hidnplayr	848	.econnrefused:
6908	ashmew2	849	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Connection refused\n"
3545	hidnplayr	850	mov [ebx + SOCKET.errorcode], ECONNREFUSED
		851	jmp .close
		852
6476	hidnplayr	853	;-----------------------------------------------------------------------------------
3545	hidnplayr	854	.econnreset:
6908	ashmew2	855	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Connection reset\n"
3545	hidnplayr	856	mov [ebx + SOCKET.errorcode], ECONNRESET
		857	.close:
6908	ashmew2	858	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Closing connection\n"
6476	hidnplayr	859	mov [ebx + TCP_SOCKET.t_state], TCPS_CLOSED
		860	inc [TCPS_drops]
3545	hidnplayr	861
6476	hidnplayr	862
6710	clevermous	863	jmp .drop
3545	hidnplayr	864
6476	hidnplayr	865	;-----------------------------------------------------------------------------------
3545	hidnplayr	866	.rst_close:
6908	ashmew2	867	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Closing with reset\n"
6710	clevermous	868	jmp .unlock_and_close
3545	hidnplayr	869
6476	hidnplayr	870	;-----------------------------------------------------------------------------------
3545	hidnplayr	871	.no_rst:
		872
6476	hidnplayr	873	;-----------------------------------------------------------------------------------
		874	;
		875	; Handle SYN-full and ACK-less segments
		876	;
		877	;-----------------------------------------------------------------------------------
3545	hidnplayr	878
6476	hidnplayr	879	; If a SYN is in the window, then this is an error so we send an RST and drop the connection
		880
3545	hidnplayr	881	test [edx + TCP_header.Flags], TH_SYN
		882	jz .not_syn_full
		883
		884	mov eax, ebx
		885	mov ebx, ECONNRESET
6011	hidnplayr	886	call tcp_drop
3545	hidnplayr	887	jmp .drop_with_reset
		888	.not_syn_full:
		889
6476	hidnplayr	890	; If ACK bit is off, we drop the segment and return
3545	hidnplayr	891
		892	test [edx + TCP_header.Flags], TH_ACK
		893	jz .drop
		894
6476	hidnplayr	895	;----------------------------------------------------------------------------------
		896	;
		897	; ACK processing for SYN_RECEIVED state
		898	;
		899	;----------------------------------------------------------------------------------
		900
3545	hidnplayr	901	cmp [ebx + TCP_SOCKET.t_state], TCPS_SYN_RECEIVED
		902	jb .ack_processed ; states: closed, listen, syn_sent
		903	ja .no_syn_rcv ; established, fin_wait_1, fin_wait_2, close_wait, closing, last_ack, time_wait
		904
6908	ashmew2	905	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: state=syn_received\n"
3545	hidnplayr	906
		907	mov eax, [edx + TCP_header.AckNumber]
		908	cmp [ebx + TCP_SOCKET.SND_UNA], eax
		909	ja .drop_with_reset
		910	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		911	ja .drop_with_reset
		912
6476	hidnplayr	913	inc [TCPS_connects]
3545	hidnplayr	914
		915	mov eax, ebx
6011	hidnplayr	916	call socket_is_connected
3545	hidnplayr	917	mov [ebx + TCP_SOCKET.t_state], TCPS_ESTABLISHED
		918
		919	; Do window scaling?
		920
		921	test [ebx + TCP_SOCKET.t_flags], TF_RCVD_SCALE
		922	jz @f
		923	test [ebx + TCP_SOCKET.t_flags], TF_REQ_SCALE
		924	jz @f
		925
6476	hidnplayr	926	push word[ebx + TCP_SOCKET.requested_s_scale] ; Set send and receive scale factors to the received values
		927	pop word[ebx + TCP_SOCKET.SND_SCALE]
3545	hidnplayr	928	@@:
		929
6011	hidnplayr	930	call tcp_reassemble
3545	hidnplayr	931
		932	mov eax, [edx + TCP_header.SequenceNumber]
		933	dec eax
		934	mov [ebx + TCP_SOCKET.SND_WL1], eax
		935	.no_syn_rcv:
		936
6476	hidnplayr	937	;-----------------------------------------------------------------------------------
		938	;
		939	; ACK processing for SYN_RECEIVED state and higher
		940	;
		941	;-----------------------------------------------------------------------------------
		942
3545	hidnplayr	943	;-------------------------
6476	hidnplayr	944	; Check for duplicate ACKs
3545	hidnplayr	945
		946	mov eax, [edx + TCP_header.AckNumber]
		947	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
6476	hidnplayr	948	ja .dup_ack_complete
3545	hidnplayr	949
		950	test ecx, ecx
		951	jnz .reset_dupacks
		952
6476	hidnplayr	953	mov eax, dword[edx + TCP_header.Window]
3545	hidnplayr	954	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		955	jne .reset_dupacks
		956
6476	hidnplayr	957	inc [TCPS_rcvdupack]
6908	ashmew2	958	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Processing duplicate ACK\n"
3545	hidnplayr	959
		960	; If we have outstanding data, other than a window probe, this is a completely duplicate ACK
		961	; (window info didnt change) The ACK is the biggest we've seen and we've seen exactly our rexmt threshold of them,
		962	; assume a packet has been dropped and retransmit it. Kludge snd_nxt & the congestion window so we send only this one packet.
		963
3600	hidnplayr	964	test [ebx + TCP_SOCKET.timer_flags], timer_flag_retransmission
6476	hidnplayr	965	jz .reset_dupacks
3545	hidnplayr	966
		967	mov eax, [edx + TCP_header.AckNumber]
		968	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
6476	hidnplayr	969	jne .reset_dupacks
3545	hidnplayr	970
6476	hidnplayr	971	; Increment dupplicat ACK counter
		972	; If it reaches the threshold, re-transmit the missing segment
3545	hidnplayr	973
		974	inc [ebx + TCP_SOCKET.t_dupacks]
		975	cmp [ebx + TCP_SOCKET.t_dupacks], TCP_re_xmit_thresh
6476	hidnplayr	976	jb .dup_ack_complete
		977	ja .another_lost
3545	hidnplayr	978
6908	ashmew2	979	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Re-transmitting lost segment\n"
6476	hidnplayr	980
3545	hidnplayr	981	push [ebx + TCP_SOCKET.SND_NXT] ; >>>>
		982
		983	mov eax, [ebx + TCP_SOCKET.SND_WND]
		984	cmp eax, [ebx + TCP_SOCKET.SND_CWND]
4296	hidnplayr	985	jbe @f
		986	mov eax, [ebx + TCP_SOCKET.SND_CWND]
		987	@@:
3545	hidnplayr	988	shr eax, 1
		989	push edx
		990	xor edx, edx
		991	div [ebx + TCP_SOCKET.t_maxseg]
		992	cmp eax, 2
		993	ja @f
		994	xor eax, eax
		995	mov al, 2
		996	@@:
		997	mul [ebx + TCP_SOCKET.t_maxseg]
		998	pop edx
		999	mov [ebx + TCP_SOCKET.SND_SSTHRESH], eax
		1000
3600	hidnplayr	1001	and [ebx + TCP_SOCKET.timer_flags], not timer_flag_retransmission ; turn off retransmission timer
3545	hidnplayr	1002	mov [ebx + TCP_SOCKET.t_rtt], 0
		1003	mov eax, [edx + TCP_header.AckNumber]
		1004	mov [ebx + TCP_SOCKET.SND_NXT], eax
		1005	mov eax, [ebx + TCP_SOCKET.t_maxseg]
		1006	mov [ebx + TCP_SOCKET.SND_CWND], eax
		1007
		1008	; Unlock the socket
6476	hidnplayr	1009
3545	hidnplayr	1010	push ebx
		1011	lea ecx, [ebx + SOCKET.mutex]
		1012	call mutex_unlock
		1013
		1014	; retransmit missing segment
6476	hidnplayr	1015
3545	hidnplayr	1016	mov eax, [esp]
6011	hidnplayr	1017	call tcp_output
3545	hidnplayr	1018
		1019	; Lock the socket again
6476	hidnplayr	1020
3545	hidnplayr	1021	mov ecx, [esp]
		1022	add ecx, SOCKET.mutex
		1023	call mutex_lock
3711	clevermous	1024	pop ebx
3545	hidnplayr	1025
		1026	; Continue processing
6476	hidnplayr	1027
3545	hidnplayr	1028	xor edx, edx
		1029	mov eax, [ebx + TCP_SOCKET.t_maxseg]
		1030	mul [ebx + TCP_SOCKET.t_dupacks]
		1031	add eax, [ebx + TCP_SOCKET.SND_SSTHRESH]
		1032	mov [ebx + TCP_SOCKET.SND_CWND], eax
		1033
		1034	pop eax ; <<<<
		1035	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		1036	jb @f
		1037	mov [ebx + TCP_SOCKET.SND_NXT], eax
		1038	@@:
		1039	jmp .drop
		1040
6476	hidnplayr	1041	.another_lost:
6908	ashmew2	1042	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Increasing congestion window\n"
3545	hidnplayr	1043
		1044	mov eax, [ebx + TCP_SOCKET.t_maxseg]
		1045	add [ebx + TCP_SOCKET.SND_CWND], eax
		1046
		1047	; Unlock the socket
6476	hidnplayr	1048
3545	hidnplayr	1049	push ebx
		1050	lea ecx, [ebx + SOCKET.mutex]
		1051	call mutex_unlock
		1052
6476	hidnplayr	1053	; retransmit missing segment, again
		1054
3545	hidnplayr	1055	mov eax, [esp]
6011	hidnplayr	1056	call tcp_output
3545	hidnplayr	1057
		1058	; Lock the socket again
6476	hidnplayr	1059
3545	hidnplayr	1060	mov ecx, [esp]
		1061	add ecx, SOCKET.mutex
		1062	call mutex_lock
		1063	pop ebx
		1064
6476	hidnplayr	1065	; And drop the incoming segment
		1066
3545	hidnplayr	1067	jmp .drop
		1068
6476	hidnplayr	1069	.reset_dupacks: ; We got a new ACK, reset duplicate ACK counter
		1070	mov [ebx + TCP_SOCKET.t_dupacks], 0
		1071	jmp .ack_processed
3545	hidnplayr	1072
6476	hidnplayr	1073	.dup_ack_complete:
3545	hidnplayr	1074
		1075	;-------------------------------------------------
		1076	; If the congestion window was inflated to account
		1077	; for the other side's cached packets, retract it
		1078
		1079	mov eax, [ebx + TCP_SOCKET.SND_SSTHRESH]
		1080	cmp eax, [ebx + TCP_SOCKET.SND_CWND]
		1081	ja @f
		1082	cmp [ebx + TCP_SOCKET.t_dupacks], TCP_re_xmit_thresh
		1083	jbe @f
		1084	mov [ebx + TCP_SOCKET.SND_CWND], eax
		1085	@@:
		1086
		1087	mov [ebx + TCP_SOCKET.t_dupacks], 0
		1088
		1089	mov eax, [edx + TCP_header.AckNumber]
		1090	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		1091	jbe @f
5442	hidnplayr	1092	inc [TCPS_rcvacktoomuch]
3545	hidnplayr	1093	jmp .drop_after_ack
		1094	@@:
		1095
		1096	mov edi, [edx + TCP_header.AckNumber]
		1097	sub edi, [ebx + TCP_SOCKET.SND_UNA] ; now we got the number of acked bytes in edi
5442	hidnplayr	1098	inc [TCPS_rcvackpack]
		1099	add [TCPS_rcvackbyte], edi
6908	ashmew2	1100	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: acceptable ACK for %u bytes\n", edi
3545	hidnplayr	1101
6476	hidnplayr	1102	;-----------------------------------------------------------------------------------
		1103	;
4347	hidnplayr	1104	; RTT measurements and retransmission timer
6476	hidnplayr	1105	;
		1106	;-----------------------------------------------------------------------------------
3545	hidnplayr	1107
		1108	; If we have a timestamp, update smoothed RTT
		1109
4347	hidnplayr	1110	test [temp_bits], TCP_BIT_TIMESTAMP
3545	hidnplayr	1111	jz .timestamp_not_present
4344	hidnplayr	1112	mov eax, [timestamp]
3545	hidnplayr	1113	sub eax, [ebx + TCP_SOCKET.ts_ecr]
		1114	inc eax
6011	hidnplayr	1115	call tcp_xmit_timer
3545	hidnplayr	1116	jmp .rtt_done_
		1117
		1118	; If no timestamp but transmit timer is running and timed sequence number was acked,
		1119	; update smoothed RTT. Since we now have an RTT measurement, cancel the timer backoff
		1120	; (Phil Karn's retransmit algo)
		1121	; Recompute the initial retransmit timer
		1122
		1123	.timestamp_not_present:
		1124	mov eax, [edx + TCP_header.AckNumber]
		1125	cmp eax, [ebx + TCP_SOCKET.t_rtseq]
		1126	jbe .rtt_done_
		1127	mov eax, [ebx + TCP_SOCKET.t_rtt]
		1128	test eax, eax
		1129	jz .rtt_done_
6011	hidnplayr	1130	call tcp_xmit_timer
3545	hidnplayr	1131	.rtt_done_:
		1132
		1133	; If all outstanding data is acked, stop retransmit timer and remember to restart (more output or persist)
		1134	; If there is more data to be acked, restart retransmit timer, using current (possible backed-off) value.
		1135
		1136	mov eax, [ebx + TCP_SOCKET.SND_MAX]
		1137	cmp eax, [edx + TCP_header.AckNumber]
		1138	jne .more_data
3600	hidnplayr	1139	and [ebx + TCP_SOCKET.timer_flags], not timer_flag_retransmission
4347	hidnplayr	1140	or [temp_bits], TCP_BIT_NEEDOUTPUT
3545	hidnplayr	1141	jmp .no_restart
		1142	.more_data:
3600	hidnplayr	1143	test [ebx + TCP_SOCKET.timer_flags], timer_flag_persist
		1144	jnz .no_restart
3545	hidnplayr	1145
		1146	mov eax, [ebx + TCP_SOCKET.t_rxtcur]
		1147	mov [ebx + TCP_SOCKET.timer_retransmission], eax
3600	hidnplayr	1148	or [ebx + TCP_SOCKET.timer_flags], timer_flag_retransmission
3545	hidnplayr	1149	.no_restart:
		1150
6476	hidnplayr	1151	;-----------------------------------------------------------------------------------
		1152	;
3545	hidnplayr	1153	; Open congestion window in response to ACKs
6476	hidnplayr	1154	;
		1155	;-----------------------------------------------------------------------------------
3545	hidnplayr	1156
6476	hidnplayr	1157	; If the window gives us less then sstresh packets in flight, open exponentially.
		1158	; Otherwise, open lineary
		1159
3545	hidnplayr	1160	mov esi, [ebx + TCP_SOCKET.SND_CWND]
		1161	mov eax, [ebx + TCP_SOCKET.t_maxseg]
		1162	cmp esi, [ebx + TCP_SOCKET.SND_SSTHRESH]
		1163	jbe @f
		1164	push edx
		1165	push eax
6476	hidnplayr	1166	mul eax ; t_maxseg*t_maxseg
		1167	div esi ; t_maxseg*t_maxseg/snd_cwnd
		1168	pop edx ; t_maxseg
		1169	shr edx, 3 ; t_maxseg/8
		1170	add eax, edx ; t_maxseg*t_maxseg/snd_cwnd + t_maxseg/8
3545	hidnplayr	1171	pop edx
		1172	@@:
		1173	add esi, eax
		1174
		1175	push ecx
		1176	mov cl, [ebx + TCP_SOCKET.SND_SCALE]
		1177	mov eax, TCP_max_win
		1178	shl eax, cl
		1179	pop ecx
		1180
		1181	cmp esi, eax
4296	hidnplayr	1182	jbe @f
		1183	mov esi, eax
		1184	@@:
3545	hidnplayr	1185	mov [ebx + TCP_SOCKET.SND_CWND], esi
		1186
6476	hidnplayr	1187	;-----------------------------------------------------------------------------------
		1188	;
3545	hidnplayr	1189	; Remove acknowledged data from send buffer
6476	hidnplayr	1190	;
		1191	;-----------------------------------------------------------------------------------
3545	hidnplayr	1192
6476	hidnplayr	1193	; If the number of bytes acknowledged exceeds the number of bytes on the send buffer,
		1194	; snd_wnd is decremented by the number of bytes in the send buffer and TCP knows
		1195	; that its FIN has been ACKed. (FIN occupies 1 byte in the sequence number space)
		1196
3545	hidnplayr	1197	cmp edi, [ebx + STREAM_SOCKET.snd.size]
6476	hidnplayr	1198	jbe .no_fin_ack
3545	hidnplayr	1199
6476	hidnplayr	1200	; Drop all data in output buffer
		1201
3545	hidnplayr	1202	push ecx edx ebx
		1203	mov ecx, [ebx + STREAM_SOCKET.snd.size]
6476	hidnplayr	1204	sub [ebx + TCP_SOCKET.SND_WND], ecx
3545	hidnplayr	1205	lea eax, [ebx + STREAM_SOCKET.snd]
6011	hidnplayr	1206	call socket_ring_free
3545	hidnplayr	1207	pop ebx edx ecx
		1208
6908	ashmew2	1209	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: our FIN is acked\n"
5133	hidnplayr	1210	or [temp_bits], TCP_BIT_FIN_IS_ACKED
6476	hidnplayr	1211	jmp .ack_complete
		1212	.no_fin_ack:
3545	hidnplayr	1213
6476	hidnplayr	1214	; Drop acknowledged data
3545	hidnplayr	1215
		1216	push ecx edx ebx
		1217	mov ecx, edi
		1218	lea eax, [ebx + STREAM_SOCKET.snd]
6011	hidnplayr	1219	call socket_ring_free
3545	hidnplayr	1220	pop ebx
		1221	sub [ebx + TCP_SOCKET.SND_WND], ecx
		1222	pop edx ecx
6476	hidnplayr	1223	.ack_complete:
3545	hidnplayr	1224
6476	hidnplayr	1225	;-----------------------------------------------------------------------------------
		1226	;
3545	hidnplayr	1227	; Wake up process waiting on send buffer
6476	hidnplayr	1228	;
		1229	;-----------------------------------------------------------------------------------
3545	hidnplayr	1230
		1231	mov eax, ebx
6011	hidnplayr	1232	call socket_notify
3545	hidnplayr	1233
		1234	; Update TCPS
6476	hidnplayr	1235
3545	hidnplayr	1236	mov eax, [edx + TCP_header.AckNumber]
		1237	mov [ebx + TCP_SOCKET.SND_UNA], eax
		1238	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		1239	jb @f
		1240	mov [ebx + TCP_SOCKET.SND_NXT], eax
		1241	@@:
		1242
6476	hidnplayr	1243	;-----------------------------------------------------------------------------------
		1244	;
		1245	; State specific ACK handeling
		1246	;
		1247	;-----------------------------------------------------------------------------------
3545	hidnplayr	1248
		1249	mov eax, [ebx + TCP_SOCKET.t_state]
6476	hidnplayr	1250	jmp dword[.ack_sw_list+eax*4]
3545	hidnplayr	1251
6476	hidnplayr	1252	.ack_sw_list:
3545	hidnplayr	1253	dd .ack_processed ; TCPS_CLOSED
		1254	dd .ack_processed ; TCPS_LISTEN
		1255	dd .ack_processed ; TCPS_SYN_SENT
		1256	dd .ack_processed ; TCPS_SYN_RECEIVED
		1257	dd .ack_processed ; TCPS_ESTABLISHED
		1258	dd .ack_processed ; TCPS_CLOSE_WAIT
		1259	dd .ack_fw1 ; TCPS_FIN_WAIT_1
		1260	dd .ack_c ; TCPS_CLOSING
		1261	dd .ack_la ; TCPS_LAST_ACK
		1262	dd .ack_processed ; TCPS_FIN_WAIT_2
		1263	dd .ack_tw ; TCPS_TIMED_WAIT
		1264
6476	hidnplayr	1265	;-----------------------------------------------------------------------------------
		1266	.ack_fw1:
		1267	; If our FIN is now acked, enter FIN_WAIT_2
3545	hidnplayr	1268
5133	hidnplayr	1269	test [temp_bits], TCP_BIT_FIN_IS_ACKED
		1270	jz .ack_processed
3545	hidnplayr	1271
6476	hidnplayr	1272	; If we can't receive any more data, then closing user can proceed.
		1273	; Starting the timer is contrary to the specification, but if we dont get a FIN,
		1274	; we'll hang forever.
		1275
3545	hidnplayr	1276	test [ebx + SOCKET.state], SS_CANTRCVMORE
7974	hidnplayr	1277	jz @f
3545	hidnplayr	1278	mov eax, ebx
6011	hidnplayr	1279	call socket_is_disconnected
3545	hidnplayr	1280	mov [ebx + TCP_SOCKET.timer_timed_wait], TCP_time_max_idle
3600	hidnplayr	1281	or [ebx + TCP_SOCKET.timer_flags], timer_flag_wait
3545	hidnplayr	1282	@@:
		1283	mov [ebx + TCP_SOCKET.t_state], TCPS_FIN_WAIT_2
		1284	jmp .ack_processed
		1285
6476	hidnplayr	1286	;-----------------------------------------------------------------------------------
3545	hidnplayr	1287	.ack_c:
6476	hidnplayr	1288	; Enter the TIME_WAIT state if our FIN is acked in CLOSED state.
		1289
5133	hidnplayr	1290	test [temp_bits], TCP_BIT_FIN_IS_ACKED
		1291	jz .ack_processed
3545	hidnplayr	1292
6476	hidnplayr	1293	mov [ebx + TCP_SOCKET.t_state], TCPS_TIME_WAIT
3545	hidnplayr	1294	mov eax, ebx
6011	hidnplayr	1295	call tcp_cancel_timers
3545	hidnplayr	1296	mov [ebx + TCP_SOCKET.timer_timed_wait], 2 * TCP_time_MSL
3600	hidnplayr	1297	or [ebx + TCP_SOCKET.timer_flags], timer_flag_wait
3545	hidnplayr	1298	mov eax, ebx
6011	hidnplayr	1299	call socket_is_disconnected
3545	hidnplayr	1300	jmp .ack_processed
		1301
6476	hidnplayr	1302	;-----------------------------------------------------------------------------------
3545	hidnplayr	1303	.ack_la:
6476	hidnplayr	1304	; In LAST_ACK state, we may still be waiting for data to drain and/or to be acked.
		1305	; If our FIN is acked however, enter CLOSED state and return.
		1306
5133	hidnplayr	1307	test [temp_bits], TCP_BIT_FIN_IS_ACKED
		1308	jz .ack_processed
3545	hidnplayr	1309
6710	clevermous	1310	.unlock_and_close:
3652	hidnplayr	1311	push ebx
		1312	lea ecx, [ebx + SOCKET.mutex]
		1313	call mutex_unlock
6476	hidnplayr	1314	pop eax
3652	hidnplayr	1315
6011	hidnplayr	1316	call tcp_close
4366	hidnplayr	1317	jmp .drop_no_socket
3545	hidnplayr	1318
6476	hidnplayr	1319	;-----------------------------------------------------------------------------------
3545	hidnplayr	1320	.ack_tw:
6476	hidnplayr	1321	; In TIME_WAIT state the only thing that should arrive is a retransmission of the remote FIN.
		1322	; Acknowledge it and restart the FINACK timer
		1323
		1324	mov [ebx + TCP_SOCKET.timer_timed_wait], 2*TCP_time_MSL
		1325	or [ebx + TCP_SOCKET.timer_flags], timer_flag_2msl
3545	hidnplayr	1326	jmp .drop_after_ack
		1327
6476	hidnplayr	1328	;-----------------------------------------------------------------------------------
		1329	;
		1330	; Initiation of Passive Open?
		1331	;
		1332	;-----------------------------------------------------------------------------------
3545	hidnplayr	1333
6476	hidnplayr	1334	.state_listen:
6908	ashmew2	1335	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: state=listen\n"
3545	hidnplayr	1336
		1337	test [edx + TCP_header.Flags], TH_RST
		1338	jnz .drop
		1339
		1340	test [edx + TCP_header.Flags], TH_ACK
		1341	jnz .drop_with_reset
		1342
		1343	test [edx + TCP_header.Flags], TH_SYN
		1344	jz .drop
		1345
6476	hidnplayr	1346	inc [TCPS_accepts]
5442	hidnplayr	1347
3545	hidnplayr	1348	;;; TODO: check if it's a broadcast or multicast, and drop if so
		1349
6476	hidnplayr	1350	;-------------------------------------------
		1351	; Processing of SYN received in LISTEN state
		1352
5842	hidnplayr	1353	push [edi + IPv4_header.SourceAddress]
3545	hidnplayr	1354	pop [ebx + IP_SOCKET.RemoteIP]
		1355
		1356	push [edx + TCP_header.SourcePort]
		1357	pop [ebx + TCP_SOCKET.RemotePort]
		1358
		1359	push [edx + TCP_header.SequenceNumber]
		1360	pop [ebx + TCP_SOCKET.IRS]
		1361
		1362	mov eax, [TCP_sequence_num]
6476	hidnplayr	1363	add [TCP_sequence_num], TCP_ISSINCR / 2
3545	hidnplayr	1364	mov [ebx + TCP_SOCKET.ISS], eax
		1365	mov [ebx + TCP_SOCKET.SND_NXT], eax
		1366
6011	hidnplayr	1367	tcp_sendseqinit ebx
		1368	tcp_rcvseqinit ebx
3545	hidnplayr	1369
		1370	mov [ebx + TCP_SOCKET.t_state], TCPS_SYN_RECEIVED
4347	hidnplayr	1371	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
3545	hidnplayr	1372	mov [ebx + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval ;;;; macro
3600	hidnplayr	1373	or [ebx + TCP_SOCKET.timer_flags], timer_flag_keepalive
3545	hidnplayr	1374
		1375	lea eax, [ebx + STREAM_SOCKET.snd]
6011	hidnplayr	1376	call socket_ring_create
5155	hidnplayr	1377	test eax, eax
		1378	jz .drop
3545	hidnplayr	1379
		1380	lea eax, [ebx + STREAM_SOCKET.rcv]
6011	hidnplayr	1381	call socket_ring_create
5155	hidnplayr	1382	test eax, eax
		1383	jz .drop
3545	hidnplayr	1384
4347	hidnplayr	1385	and [temp_bits], not TCP_BIT_DROPSOCKET
3545	hidnplayr	1386
3674	hidnplayr	1387	pusha
		1388	mov eax, ebx
6011	hidnplayr	1389	call socket_notify
3674	hidnplayr	1390	popa
3545	hidnplayr	1391
5133	hidnplayr	1392	jmp .trim
3545	hidnplayr	1393
6476	hidnplayr	1394	;-----------------------------------------------------------------------------------
		1395	;
		1396	; Completion of active open?
		1397	;
		1398	;-----------------------------------------------------------------------------------
3545	hidnplayr	1399
6476	hidnplayr	1400	.state_syn_sent:
6908	ashmew2	1401	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: state=syn_sent\n"
3545	hidnplayr	1402
		1403	test [edx + TCP_header.Flags], TH_ACK
		1404	jz @f
		1405
		1406	mov eax, [edx + TCP_header.AckNumber]
		1407	cmp eax, [ebx + TCP_SOCKET.ISS]
		1408	jbe .drop_with_reset
		1409
		1410	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		1411	ja .drop_with_reset
		1412	@@:
		1413
		1414	test [edx + TCP_header.Flags], TH_RST
		1415	jz @f
		1416
		1417	test [edx + TCP_header.Flags], TH_ACK
		1418	jz .drop
		1419
		1420	mov eax, ebx
		1421	mov ebx, ECONNREFUSED
6011	hidnplayr	1422	call tcp_drop
3545	hidnplayr	1423	jmp .drop
		1424	@@:
		1425
6476	hidnplayr	1426	;-----------------------------------------------------------------------------------
		1427	;
		1428	; Process received SYN in response to an active open
		1429	;
		1430	;-----------------------------------------------------------------------------------
		1431
3545	hidnplayr	1432	test [edx + TCP_header.Flags], TH_SYN
		1433	jz .drop
		1434
		1435	test [edx + TCP_header.Flags], TH_ACK
6476	hidnplayr	1436	jz @f
3545	hidnplayr	1437
		1438	mov eax, [edx + TCP_header.AckNumber]
		1439	mov [ebx + TCP_SOCKET.SND_UNA], eax
		1440	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		1441	jbe @f
		1442	mov [ebx + TCP_SOCKET.SND_NXT], eax
		1443
3600	hidnplayr	1444	and [ebx + TCP_SOCKET.timer_flags], not timer_flag_retransmission ; disable retransmission timer
6476	hidnplayr	1445	@@:
3545	hidnplayr	1446
		1447	push [edx + TCP_header.SequenceNumber]
		1448	pop [ebx + TCP_SOCKET.IRS]
		1449
6011	hidnplayr	1450	tcp_rcvseqinit ebx
3545	hidnplayr	1451
		1452	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
		1453
		1454	mov eax, [ebx + TCP_SOCKET.SND_UNA]
		1455	cmp eax, [ebx + TCP_SOCKET.ISS]
		1456	jbe .simultaneous_open
		1457
		1458	test [edx + TCP_header.Flags], TH_ACK
		1459	jz .simultaneous_open
		1460
6908	ashmew2	1461	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: active open\n"
3545	hidnplayr	1462
6476	hidnplayr	1463	inc [TCPS_connects]
3545	hidnplayr	1464
		1465	; set socket state to connected
6476	hidnplayr	1466
3674	hidnplayr	1467	push eax
		1468	mov eax, ebx
6011	hidnplayr	1469	call socket_is_connected
3674	hidnplayr	1470	pop eax
3545	hidnplayr	1471	mov [ebx + TCP_SOCKET.t_state], TCPS_ESTABLISHED
		1472
		1473	; Do window scaling on this connection ?
6476	hidnplayr	1474
3545	hidnplayr	1475	mov eax, [ebx + TCP_SOCKET.t_flags]
		1476	and eax, TF_REQ_SCALE or TF_RCVD_SCALE
		1477	cmp eax, TF_REQ_SCALE or TF_RCVD_SCALE
		1478	jne .no_scaling
		1479
6011	hidnplayr	1480	mov ax, word[ebx + TCP_SOCKET.requested_s_scale]
		1481	mov word[ebx + TCP_SOCKET.SND_SCALE], ax
3545	hidnplayr	1482	.no_scaling:
		1483
		1484	;;; TODO: reassemble packets queue
		1485
6476	hidnplayr	1486	; If we didnt have time to re-transmit the SYN,
		1487	; Use its rtt as our initial srtt & rtt var.
		1488
3545	hidnplayr	1489	mov eax, [ebx + TCP_SOCKET.t_rtt]
		1490	test eax, eax
5133	hidnplayr	1491	je .trim
6011	hidnplayr	1492	call tcp_xmit_timer
5133	hidnplayr	1493	jmp .trim
3545	hidnplayr	1494
6476	hidnplayr	1495	;-----------------------------------------------------------------------------------
		1496	;
		1497	; Simultaneous open (We have received a SYN but no ACK)
		1498	;
		1499	;-----------------------------------------------------------------------------------
		1500
3545	hidnplayr	1501	.simultaneous_open:
6908	ashmew2	1502	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: simultaneous open\n"
3545	hidnplayr	1503	mov [ebx + TCP_SOCKET.t_state], TCPS_SYN_RECEIVED
		1504
6476	hidnplayr	1505	;-----------------------------------------------------------------------------------
		1506	;
3545	hidnplayr	1507	; Common processing for receipt of SYN
6476	hidnplayr	1508	;
		1509	;-----------------------------------------------------------------------------------
3545	hidnplayr	1510
5133	hidnplayr	1511	.trim:
6476	hidnplayr	1512	; Advance sequence number to correspond to first data byte.
		1513	; If data, trim to stay within window, dropping FIN if necessary
		1514
3545	hidnplayr	1515	inc [edx + TCP_header.SequenceNumber]
		1516
4339	hidnplayr	1517	; Drop any received data that doesnt fit in the receive window.
6476	hidnplayr	1518
4339	hidnplayr	1519	cmp ecx, [ebx + TCP_SOCKET.RCV_WND]
		1520	jbe .dont_trim
3545	hidnplayr	1521
6908	ashmew2	1522	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: received data does not fit in window, trimming %u bytes\n", eax
6476	hidnplayr	1523	inc [TCPS_rcvpackafterwin]
		1524	sub ecx, [ebx + TCP_SOCKET.RCV_WND]
		1525	add [TCPS_rcvbyteafterwin], ecx
		1526
		1527	and [edx + TCP_header.Flags], not (TH_FIN)
4339	hidnplayr	1528	mov ecx, [ebx + TCP_SOCKET.RCV_WND]
		1529
		1530	.dont_trim:
3545	hidnplayr	1531	mov eax, [edx + TCP_header.SequenceNumber]
		1532	mov [ebx + TCP_SOCKET.RCV_UP], eax
		1533	dec eax
		1534	mov [ebx + TCP_SOCKET.SND_WL1], eax
		1535
6476	hidnplayr	1536	;-----------------------------------------------------------------------------------
		1537	;
		1538	; Update window information (step 6 in RFC793)
		1539	;
		1540	;-----------------------------------------------------------------------------------
		1541
3545	hidnplayr	1542	.ack_processed:
6908	ashmew2	1543	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: ACK processed\n"
3545	hidnplayr	1544
6476	hidnplayr	1545	; dont look at window if no ACK
3545	hidnplayr	1546
		1547	test [edx + TCP_header.Flags], TH_ACK
		1548	jz .no_window_update
		1549
6476	hidnplayr	1550	; Does the segment contain new data?
		1551
3545	hidnplayr	1552	mov eax, [ebx + TCP_SOCKET.SND_WL1]
		1553	cmp eax, [edx + TCP_header.SequenceNumber]
		1554	jb .update_window
		1555	ja @f
		1556
6476	hidnplayr	1557	; No new data but a new ACK ?
		1558
3545	hidnplayr	1559	mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1560	cmp eax, [edx + TCP_header.AckNumber]
		1561	jb .update_window
		1562	@@:
		1563
6476	hidnplayr	1564	; No new data or ACK but advertised window is larger then current window?
		1565
		1566	mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1567	cmp eax, [edx + TCP_header.AckNumber]
		1568	jne .no_window_update
		1569
		1570	mov eax, dword[edx + TCP_header.Window]
3545	hidnplayr	1571	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		1572	jbe .no_window_update
		1573
6476	hidnplayr	1574
		1575	; Keep track of pure window updates
3545	hidnplayr	1576	.update_window:
6476	hidnplayr	1577	test ecx, ecx
		1578	jnz @f
		1579	mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1580	cmp eax, [edx + TCP_header.AckNumber]
		1581	jne @f
		1582	mov eax, dword[edx + TCP_header.Window]
		1583	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		1584	jbe @f
		1585	inc [TCPS_rcvwinupd]
		1586	@@:
3545	hidnplayr	1587
6476	hidnplayr	1588	mov eax, dword[edx + TCP_header.Window]
		1589	mov [ebx + TCP_SOCKET.SND_WND], eax
3545	hidnplayr	1590	cmp eax, [ebx + TCP_SOCKET.max_sndwnd]
		1591	jbe @f
		1592	mov [ebx + TCP_SOCKET.max_sndwnd], eax
		1593	@@:
		1594
6908	ashmew2	1595	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Updating window to %u\n", eax
3545	hidnplayr	1596
		1597	push [edx + TCP_header.SequenceNumber]
		1598	pop [ebx + TCP_SOCKET.SND_WL1]
		1599
		1600	push [edx + TCP_header.AckNumber]
		1601	pop [ebx + TCP_SOCKET.SND_WL2]
		1602
4347	hidnplayr	1603	or [temp_bits], TCP_BIT_NEEDOUTPUT
3545	hidnplayr	1604	.no_window_update:
		1605
6476	hidnplayr	1606	;-----------------------------------------------------------------------------------
		1607	;
		1608	; Process URG flag
		1609	;
		1610	;-----------------------------------------------------------------------------------
3545	hidnplayr	1611
		1612	test [edx + TCP_header.Flags], TH_URG
		1613	jz .not_urgent
		1614
		1615	cmp [edx + TCP_header.UrgentPointer], 0
		1616	jz .not_urgent
		1617
6476	hidnplayr	1618	cmp [ebx + TCP_SOCKET.t_state], TCPS_TIME_WAIT
3545	hidnplayr	1619	je .not_urgent
		1620
		1621	; Ignore bogus urgent offsets
		1622
		1623	movzx eax, [edx + TCP_header.UrgentPointer]
		1624	add eax, [ebx + STREAM_SOCKET.rcv.size]
6413	hidnplayr	1625	cmp eax, SOCKET_BUFFER_SIZE
3545	hidnplayr	1626	jbe .not_urgent
		1627
		1628	mov [edx + TCP_header.UrgentPointer], 0
		1629	and [edx + TCP_header.Flags], not (TH_URG)
		1630	jmp .do_data
		1631
		1632	.not_urgent:
		1633
		1634	; processing of received urgent pointer
		1635
		1636	;;; TODO (1051-1093)
		1637
6476	hidnplayr	1638	;-----------------------------------------------------------------------------------
		1639	;
		1640	; Process the data
		1641	;
		1642	;-----------------------------------------------------------------------------------
3545	hidnplayr	1643
		1644	.do_data:
6476	hidnplayr	1645	cmp [ebx + TCP_SOCKET.t_state], TCPS_TIME_WAIT
3545	hidnplayr	1646	jae .final_processing
		1647
		1648	test [edx + TCP_header.Flags], TH_FIN
		1649	jnz @f
		1650
		1651	test ecx, ecx
3756	hidnplayr	1652	jz .final_processing
3545	hidnplayr	1653	@@:
		1654
		1655	; The segment is in order?
6476	hidnplayr	1656
3545	hidnplayr	1657	mov eax, [edx + TCP_header.SequenceNumber]
		1658	cmp eax, [ebx + TCP_SOCKET.RCV_NXT]
		1659	jne .out_of_order
		1660
		1661	; The reassembly queue is empty?
6476	hidnplayr	1662
3545	hidnplayr	1663	cmp [ebx + TCP_SOCKET.seg_next], 0
		1664	jne .out_of_order
		1665
		1666	; The connection is established?
6476	hidnplayr	1667
3545	hidnplayr	1668	cmp [ebx + TCP_SOCKET.t_state], TCPS_ESTABLISHED
		1669	jne .out_of_order
		1670
		1671	; Ok, lets do this.. Set delayed ACK flag and copy data into socket buffer
6476	hidnplayr	1672
3545	hidnplayr	1673	or [ebx + TCP_SOCKET.t_flags], TF_DELACK
		1674
		1675	pusha
4339	hidnplayr	1676	mov esi, [dataoffset]
3545	hidnplayr	1677	add esi, edx
		1678	lea eax, [ebx + STREAM_SOCKET.rcv]
6011	hidnplayr	1679	call socket_ring_write ; Add the data to the socket buffer
3545	hidnplayr	1680	add [ebx + TCP_SOCKET.RCV_NXT], ecx ; Update sequence number with number of bytes we have copied
		1681	popa
		1682
		1683	; Wake up the sleeping process
6476	hidnplayr	1684
3545	hidnplayr	1685	mov eax, ebx
6011	hidnplayr	1686	call socket_notify
3545	hidnplayr	1687
		1688	jmp .data_done
		1689
		1690	.out_of_order:
6908	ashmew2	1691	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP data is out of order!\nSequencenumber is %u, we expected %u.\n", \
4339	hidnplayr	1692	[edx + TCP_header.SequenceNumber], [ebx + TCP_SOCKET.RCV_NXT]
3545	hidnplayr	1693
		1694	; Uh-oh, some data is out of order, lets call TCP reassemble for help
		1695
6915	hidnplayr	1696	call tcp_reassemble ;;; TODO!
3545	hidnplayr	1697
4339	hidnplayr	1698	; Generate ACK immediately, to let the other end know that a segment was received out of order,
		1699	; and to tell it what sequence number is expected. This aids the fast-retransmit algorithm.
6476	hidnplayr	1700
3545	hidnplayr	1701	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
6915	hidnplayr	1702
		1703	jmp .final_processing ;;; HACK because of unimplemented reassembly queue!
3545	hidnplayr	1704	.data_done:
		1705
6476	hidnplayr	1706	;-----------------------------------------------------------------------------------
		1707	;
		1708	; Process FIN
		1709	;
		1710	;-----------------------------------------------------------------------------------
3545	hidnplayr	1711
		1712	test [edx + TCP_header.Flags], TH_FIN
		1713	jz .final_processing
		1714
6908	ashmew2	1715	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Processing FIN\n"
3545	hidnplayr	1716
6476	hidnplayr	1717	cmp [ebx + TCP_SOCKET.t_state], TCPS_TIME_WAIT
3545	hidnplayr	1718	jae .not_first_fin
		1719
6908	ashmew2	1720	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: First FIN for this connection\n"
3545	hidnplayr	1721
		1722	mov eax, ebx
6011	hidnplayr	1723	call socket_cant_recv_more
3545	hidnplayr	1724
4347	hidnplayr	1725	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
3545	hidnplayr	1726	inc [ebx + TCP_SOCKET.RCV_NXT]
		1727
		1728	.not_first_fin:
		1729	mov eax, [ebx + TCP_SOCKET.t_state]
6476	hidnplayr	1730	jmp dword[.fin_sw_list+eax*4]
3545	hidnplayr	1731
6476	hidnplayr	1732	.fin_sw_list:
3545	hidnplayr	1733	dd .final_processing ; TCPS_CLOSED
		1734	dd .final_processing ; TCPS_LISTEN
		1735	dd .final_processing ; TCPS_SYN_SENT
		1736	dd .fin_syn_est ; TCPS_SYN_RECEIVED
		1737	dd .fin_syn_est ; TCPS_ESTABLISHED
		1738	dd .final_processing ; TCPS_CLOSE_WAIT
		1739	dd .fin_wait1 ; TCPS_FIN_WAIT_1
		1740	dd .final_processing ; TCPS_CLOSING
		1741	dd .final_processing ; TCPS_LAST_ACK
		1742	dd .fin_wait2 ; TCPS_FIN_WAIT_2
		1743	dd .fin_timed ; TCPS_TIMED_WAIT
		1744
6476	hidnplayr	1745	;-----------------------------------------------------------------------------------
3545	hidnplayr	1746	.fin_syn_est:
6476	hidnplayr	1747	; In SYN_RECEIVED and ESTABLISHED state, enter the CLOSE_WAIT state
		1748
3545	hidnplayr	1749	mov [ebx + TCP_SOCKET.t_state], TCPS_CLOSE_WAIT
		1750	jmp .final_processing
		1751
6476	hidnplayr	1752	;-----------------------------------------------------------------------------------
3545	hidnplayr	1753	.fin_wait1:
6476	hidnplayr	1754	; From FIN_WAIT_1 state, enter CLOSING state (our FIN has not been ACKed)
		1755
3545	hidnplayr	1756	mov [ebx + TCP_SOCKET.t_state], TCPS_CLOSING
		1757	jmp .final_processing
		1758
6476	hidnplayr	1759	;-----------------------------------------------------------------------------------
3545	hidnplayr	1760	.fin_wait2:
6476	hidnplayr	1761	; From FIN_WAIT_2 state, enter TIME_WAIT state and start the timer
		1762
		1763	mov [ebx + TCP_SOCKET.t_state], TCPS_TIME_WAIT
3545	hidnplayr	1764	mov eax, ebx
6011	hidnplayr	1765	call tcp_cancel_timers
		1766	call socket_is_disconnected
3545	hidnplayr	1767
6476	hidnplayr	1768	;-----------------------------------------------------------------------------------
3545	hidnplayr	1769	.fin_timed:
6476	hidnplayr	1770	; (re)start the 2 MSL timer
3545	hidnplayr	1771	mov [ebx + TCP_SOCKET.timer_timed_wait], 2 * TCP_time_MSL
3600	hidnplayr	1772	or [ebx + TCP_SOCKET.timer_flags], timer_flag_wait
3545	hidnplayr	1773
6476	hidnplayr	1774	;-----------------------------------------------------------------------------------
		1775	;
		1776	; Finally, drop the segment
		1777	;
		1778	;-----------------------------------------------------------------------------------
3545	hidnplayr	1779
4347	hidnplayr	1780	.final_processing:
6908	ashmew2	1781	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Final processing\n"
4347	hidnplayr	1782
		1783	push ebx
		1784	lea ecx, [ebx + SOCKET.mutex]
		1785	call mutex_unlock
		1786	pop eax
		1787
		1788	test [temp_bits], TCP_BIT_NEEDOUTPUT
		1789	jnz .need_output
		1790
		1791	test [eax + TCP_SOCKET.t_flags], TF_ACKNOW
5133	hidnplayr	1792	jz .done
6908	ashmew2	1793	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: ACK now!\n"
4347	hidnplayr	1794
		1795	.need_output:
6908	ashmew2	1796	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: need output\n"
6011	hidnplayr	1797	call tcp_output
4347	hidnplayr	1798
5133	hidnplayr	1799	.done:
6908	ashmew2	1800	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: dumping\n"
4347	hidnplayr	1801
6011	hidnplayr	1802	call net_buff_free
4347	hidnplayr	1803	jmp .loop
		1804
6476	hidnplayr	1805	;-----------------------------------------------------------------------------------
		1806	;
		1807	; Drop segment, reply with an RST segment when needed
		1808	;
		1809	;-----------------------------------------------------------------------------------
4347	hidnplayr	1810
6476	hidnplayr	1811	;-----------------------------------------------------------------------------------
3545	hidnplayr	1812	.drop_after_ack:
6908	ashmew2	1813	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Drop after ACK\n"
3545	hidnplayr	1814
		1815	push edx ebx
		1816	lea ecx, [ebx + SOCKET.mutex]
		1817	call mutex_unlock
		1818	pop eax edx
		1819
		1820	test [edx + TCP_header.Flags], TH_RST
5133	hidnplayr	1821	jnz .done
3545	hidnplayr	1822
		1823	or [eax + TCP_SOCKET.t_flags], TF_ACKNOW
		1824	jmp .need_output
		1825
6476	hidnplayr	1826	;-----------------------------------------------------------------------------------
3545	hidnplayr	1827	.drop_with_reset:
6908	ashmew2	1828	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Drop with reset\n"
3545	hidnplayr	1829
		1830	push ebx edx
		1831	lea ecx, [ebx + SOCKET.mutex]
		1832	call mutex_unlock
		1833	pop edx ebx
		1834
		1835	test [edx + TCP_header.Flags], TH_RST
5133	hidnplayr	1836	jnz .done
3545	hidnplayr	1837
6011	hidnplayr	1838	; TODO: if its a multicast/broadcast, also drop
3545	hidnplayr	1839
		1840	test [edx + TCP_header.Flags], TH_ACK
		1841	jnz .respond_ack
		1842
		1843	test [edx + TCP_header.Flags], TH_SYN
		1844	jnz .respond_syn
5133	hidnplayr	1845	jmp .done
3545	hidnplayr	1846
		1847	.respond_ack:
		1848	push ebx
		1849	mov cl, TH_RST
6011	hidnplayr	1850	call tcp_respond
3545	hidnplayr	1851	pop ebx
		1852	jmp .destroy_new_socket
		1853
		1854	.respond_syn:
		1855	push ebx
		1856	mov cl, TH_RST + TH_ACK
6011	hidnplayr	1857	call tcp_respond
3545	hidnplayr	1858	pop ebx
		1859	jmp .destroy_new_socket
		1860
5133	hidnplayr	1861	;-----------------------------------------
		1862	; The connection has no associated socket
		1863
3647	hidnplayr	1864	.no_socket:
		1865	pusha
		1866	mov ecx, socket_mutex
		1867	call mutex_unlock
		1868	popa
		1869
3545	hidnplayr	1870	.respond_seg_reset:
		1871	test [edx + TCP_header.Flags], TH_RST
		1872	jnz .drop_no_socket
		1873
6011	hidnplayr	1874	; TODO: if its a multicast/broadcast, also drop
3545	hidnplayr	1875
		1876	test [edx + TCP_header.Flags], TH_ACK
		1877	jnz .respond_seg_ack
		1878
		1879	test [edx + TCP_header.Flags], TH_SYN
		1880	jnz .respond_seg_syn
		1881
		1882	jmp .drop_no_socket
		1883
		1884	.respond_seg_ack:
		1885	mov cl, TH_RST
6910	hidnplayr	1886	mov ebx, [device]
6011	hidnplayr	1887	call tcp_respond_segment
3545	hidnplayr	1888	jmp .drop_no_socket
		1889
		1890	.respond_seg_syn:
		1891	mov cl, TH_RST + TH_ACK
6910	hidnplayr	1892	mov ebx, [device]
6011	hidnplayr	1893	call tcp_respond_segment
3545	hidnplayr	1894	jmp .drop_no_socket
		1895
5133	hidnplayr	1896	;------------------------------------------------
		1897	; Unlock socket mutex and prepare to drop segment
3545	hidnplayr	1898
		1899	.drop:
6908	ashmew2	1900	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Dropping segment\n"
3545	hidnplayr	1901
		1902	pusha
		1903	lea ecx, [ebx + SOCKET.mutex]
		1904	call mutex_unlock
		1905	popa
		1906
5133	hidnplayr	1907	;--------------------------------------------
		1908	; Destroy the newly created socket if needed
		1909
3545	hidnplayr	1910	.destroy_new_socket:
4347	hidnplayr	1911	test [temp_bits], TCP_BIT_DROPSOCKET
3545	hidnplayr	1912	jz .drop_no_socket
		1913
		1914	mov eax, ebx
6011	hidnplayr	1915	call socket_free
3545	hidnplayr	1916
5133	hidnplayr	1917	;------------------
		1918	; Drop the segment
		1919
3545	hidnplayr	1920	.drop_no_socket:
6908	ashmew2	1921	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Drop (no socket)\n"
3545	hidnplayr	1922
6011	hidnplayr	1923	call net_buff_free
3545	hidnplayr	1924	jmp .loop
4339	hidnplayr	1925
		1926	endp

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(root)/kernel/trunk/network/tcp_input.inc @ 5521 – Rev 10051