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

Rev	Author	Line No.	Line
3545	hidnplayr	1	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
		2	;; ;;
6476	hidnplayr	3	;; Copyright (C) KolibriOS team 2004-2016. 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: 6476 $
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:
3545	hidnplayr	40
		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 ?
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]
		108	mov ecx, [esi + TCP_queue_entry.segment_size]
5842	hidnplayr	109	mov edi, [esi + TCP_queue_entry.ip_ptr] ; ptr to ipv4 header
3545	hidnplayr	110	mov esi, [esi + TCP_queue_entry.segment_ptr] ; change esi last
		111
3556	hidnplayr	112	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: size=%u time=%d\n", ecx, [timer_ticks]
3545	hidnplayr	113
		114	mov edx, esi
		115
6476	hidnplayr	116	; Verify the checksum (if not already done by hw)
3545	hidnplayr	117
4388	hidnplayr	118	test [ebx + NET_DEVICE.hwacc], NET_HWACC_TCP_IPv4_IN
		119	jnz .checksum_ok
3545	hidnplayr	120
		121	push ecx esi
		122	pushw [esi + TCP_header.Checksum]
		123	mov [esi + TCP_header.Checksum], 0
6011	hidnplayr	124	tcp_checksum (edi+IPv4_header.SourceAddress), (edi+IPv4_header.DestinationAddress)
5842	hidnplayr	125	pop cx ; previous checksum
3545	hidnplayr	126	cmp cx, dx
		127	pop edx ecx
		128	jne .drop_no_socket
		129	.checksum_ok:
		130
		131	; Verify the data offset
6476	hidnplayr	132
4339	hidnplayr	133	movzx eax, [edx + TCP_header.DataOffset]
		134	and al, 0xf0 ; Calculate TCP segment header size (throwing away unused reserved bits in TCP header)
		135	shr al, 2
		136	cmp al, sizeof.TCP_header ; Now see if it's at least the size of a standard TCP header
		137	jb .drop_no_socket ; If not, drop the packet
		138	mov [dataoffset], eax
3545	hidnplayr	139
		140	sub ecx, eax ; substract TCP header size from total segment size
		141	jb .drop_no_socket ; If total segment size is less then the advertised header size, drop packet
3556	hidnplayr	142	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: %u bytes of data\n", ecx
3545	hidnplayr	143
		144	;-------------------------------------------
		145	; Convert Big-endian values to little endian
		146
		147	ntohd [edx + TCP_header.SequenceNumber]
		148	ntohd [edx + TCP_header.AckNumber]
		149
		150	ntohw [edx + TCP_header.Window]
		151	ntohw [edx + TCP_header.UrgentPointer]
		152
6476	hidnplayr	153	;-----------------------------------------------------------------------------------
		154	;
3545	hidnplayr	155	; Find the socket pointer
6476	hidnplayr	156	;
		157	;-----------------------------------------------------------------------------------
3545	hidnplayr	158
		159	; IP Packet TCP Destination Port = local Port
		160	; (IP Packet SenderAddress = Remote IP) OR (Remote IP = 0)
		161	; (IP Packet TCP Source Port = remote Port) OR (remote Port = 0)
		162
		163	.findpcb:
3647	hidnplayr	164	pusha
		165	mov ecx, socket_mutex
		166	call mutex_lock
		167	popa
		168
3545	hidnplayr	169	mov ebx, net_sockets
		170	mov si, [edx + TCP_header.DestinationPort]
		171
		172	.socket_loop:
		173	mov ebx, [ebx + SOCKET.NextPtr]
		174	or ebx, ebx
3647	hidnplayr	175	jz .no_socket ;respond_seg_reset
3545	hidnplayr	176
		177	cmp [ebx + SOCKET.Domain], AF_INET4
		178	jne .socket_loop
		179
		180	cmp [ebx + SOCKET.Protocol], IP_PROTO_TCP
		181	jne .socket_loop
		182
		183	cmp [ebx + TCP_SOCKET.LocalPort], si
		184	jne .socket_loop
		185
		186	mov eax, [ebx + IP_SOCKET.RemoteIP]
5842	hidnplayr	187	cmp eax, [edi + IPv4_header.SourceAddress]
3545	hidnplayr	188	je @f
		189	test eax, eax
		190	jnz .socket_loop
		191	@@:
		192
		193	mov ax, [ebx + TCP_SOCKET.RemotePort]
		194	cmp [edx + TCP_header.SourcePort], ax
		195	je .found_socket
		196	test ax, ax
		197	jnz .socket_loop
		198	.found_socket: ; ebx now contains the socketpointer
3647	hidnplayr	199	pusha
		200	mov ecx, socket_mutex
		201	call mutex_unlock
		202	popa
		203
3556	hidnplayr	204	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	205
		206	;----------------------------
		207	; Check if socket isnt closed
		208
		209	cmp [ebx + TCP_SOCKET.t_state], TCPS_CLOSED
		210	je .drop_no_socket
		211
		212	;----------------
		213	; Lock the socket
		214
		215	pusha
		216	lea ecx, [ebx + SOCKET.mutex]
		217	call mutex_lock
		218	popa
		219
3556	hidnplayr	220	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: socket locked\n"
3545	hidnplayr	221
		222	;---------------------------
		223	; disable all temporary bits
		224
4347	hidnplayr	225	mov [temp_bits], 0
3545	hidnplayr	226
		227	;---------------------------------------
		228	; unscale the window into a 32 bit value
		229
		230	movzx eax, [edx + TCP_header.Window]
		231	push ecx
		232	mov cl, [ebx + TCP_SOCKET.SND_SCALE]
		233	shl eax, cl
6476	hidnplayr	234	mov dword[edx + TCP_header.Window], eax ; word after window is checksum, we dont need checksum anymore
3545	hidnplayr	235	pop ecx
		236
6476	hidnplayr	237	;-----------------------------------------------------------------------------------
		238	;
		239	; Accept incoming connections
		240	;
		241	;-----------------------------------------------------------------------------------
3545	hidnplayr	242
		243	test [ebx + SOCKET.options], SO_ACCEPTCON
		244	jz .no_accept
		245
3556	hidnplayr	246	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Accepting new connection\n"
3545	hidnplayr	247
6476	hidnplayr	248	; Unlock current socket
		249
3545	hidnplayr	250	pusha
		251	lea ecx, [ebx + SOCKET.mutex]
		252	call mutex_unlock
		253	popa
		254
6476	hidnplayr	255	; Fork it
		256
5842	hidnplayr	257	push ecx edx esi edi
6011	hidnplayr	258	call socket_fork
3545	hidnplayr	259	pop edi esi edx ecx
		260
		261	test eax, eax
		262	jz .drop_no_socket
		263
6476	hidnplayr	264	; Success! Use the new socket from now on (it is already locked)
		265
3545	hidnplayr	266	mov ebx, eax
		267
4347	hidnplayr	268	mov [temp_bits], TCP_BIT_DROPSOCKET
3545	hidnplayr	269
5842	hidnplayr	270	push [edi + IPv4_header.DestinationAddress]
3545	hidnplayr	271	pop [ebx + IP_SOCKET.LocalIP]
		272
		273	push [edx + TCP_header.DestinationPort]
		274	pop [ebx + TCP_SOCKET.LocalPort]
		275
		276	mov [ebx + TCP_SOCKET.t_state], TCPS_LISTEN
		277	.no_accept:
		278
		279
		280	;-------------------------------------
		281	; Reset idle timer and keepalive timer
		282
		283	mov [ebx + TCP_SOCKET.t_idle], 0
		284	mov [ebx + TCP_SOCKET.timer_keepalive], TCP_time_keep_idle
3600	hidnplayr	285	or [ebx + TCP_SOCKET.timer_flags], timer_flag_keepalive
3545	hidnplayr	286
6476	hidnplayr	287	;-----------------------------------------------------------------------------------
		288	;
3545	hidnplayr	289	; Process TCP options
6476	hidnplayr	290	;
		291	;-----------------------------------------------------------------------------------
3545	hidnplayr	292
4339	hidnplayr	293	;;; FIXME: for LISTEN, options should be called after we determined route, we need it for MSS
		294	;;; cmp [ebx + TCP_SOCKET.t_state], TCPS_LISTEN ; no options when in listen state
		295	;;; jz .not_uni_xfer ; also no header prediction
		296
3545	hidnplayr	297	push ecx
		298
4339	hidnplayr	299	mov ecx, [dataoffset]
6476	hidnplayr	300	cmp ecx, sizeof.TCP_header ; Does header contain any options?
3545	hidnplayr	301	je .no_options
		302
3556	hidnplayr	303	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Segment has options\n"
3545	hidnplayr	304
		305	add ecx, edx
		306	lea esi, [edx + sizeof.TCP_header]
		307
		308	.opt_loop:
		309	cmp esi, ecx ; are we scanning outside of header?
		310	jae .no_options
		311	lodsb
		312	cmp al, TCP_OPT_EOL ; end of option list?
		313	je .no_options
		314	cmp al, TCP_OPT_NOP
		315	je .opt_loop
		316	cmp al, TCP_OPT_MAXSEG
		317	je .opt_maxseg
		318	cmp al, TCP_OPT_WINDOW
		319	je .opt_window
		320	cmp al, TCP_OPT_SACK_PERMIT
		321	je .opt_sack_permit
		322	; cmp al, TCP_OPT_SACK
		323	; je .opt_sack
		324	cmp al, TCP_OPT_TIMESTAMP
		325	je .opt_timestamp
3556	hidnplayr	326	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: unknown option:%u\n", al
3545	hidnplayr	327	jmp .no_options ; If we reach here, some unknown options were received, skip them all!
		328
		329	.opt_maxseg:
		330	lodsb
		331	cmp al, 4
		332	jne .no_options ; error occured, ignore all options!
		333
		334	test [edx + TCP_header.Flags], TH_SYN
		335	jz @f
		336
4339	hidnplayr	337	xor eax, eax
3545	hidnplayr	338	lodsw
		339	rol ax, 8
4339	hidnplayr	340	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Maxseg=%u\n", eax
6011	hidnplayr	341	call tcp_mss
3545	hidnplayr	342	@@:
		343	jmp .opt_loop
		344
		345
		346	.opt_window:
		347	lodsb
		348	cmp al, 3
		349	jne .no_options
		350
		351	test [edx + TCP_header.Flags], TH_SYN
		352	jz @f
		353
3556	hidnplayr	354	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Got window scale option\n"
3545	hidnplayr	355	or [ebx + TCP_SOCKET.t_flags], TF_RCVD_SCALE
		356
		357	lodsb
		358	mov [ebx + TCP_SOCKET.SND_SCALE], al
		359	;;;;; TODO
		360
		361	@@:
		362	jmp .opt_loop
		363
		364
		365	.opt_sack_permit:
		366	lodsb
		367	cmp al, 2
		368	jne .no_options
		369
		370	test [edx + TCP_header.Flags], TH_SYN
		371	jz @f
		372
3556	hidnplayr	373	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Selective Acknowledgement permitted\n"
3545	hidnplayr	374	or [ebx + TCP_SOCKET.t_flags], TF_SACK_PERMIT
		375
		376	@@:
		377	jmp .opt_loop
		378
		379
		380	.opt_timestamp:
		381	lodsb
		382	cmp al, 10 ; length must be 10
		383	jne .no_options
		384
3556	hidnplayr	385	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Got timestamp option\n"
3545	hidnplayr	386
		387	test [edx + TCP_header.Flags], TH_SYN
		388	jz @f
		389	or [ebx + TCP_SOCKET.t_flags], TF_RCVD_TSTMP
		390	@@:
		391
		392	lodsd
4344	hidnplayr	393	bswap eax
3545	hidnplayr	394	mov [ebx + TCP_SOCKET.ts_val], eax
		395	lodsd ; timestamp echo reply
		396	mov [ebx + TCP_SOCKET.ts_ecr], eax
4347	hidnplayr	397	or [temp_bits], TCP_BIT_TIMESTAMP
3545	hidnplayr	398
		399	; Since we have a timestamp, lets do the paws test right away!
		400
		401	test [edx + TCP_header.Flags], TH_RST
		402	jnz .no_paws
		403
		404	mov eax, [ebx + TCP_SOCKET.ts_recent]
		405	test eax, eax
		406	jz .no_paws
		407	cmp eax, [ebx + TCP_SOCKET.ts_val]
4344	hidnplayr	408	jbe .no_paws
3545	hidnplayr	409
3556	hidnplayr	410	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: PAWS: detected an old segment\n"
3545	hidnplayr	411
4344	hidnplayr	412	mov eax, [timestamp]
3545	hidnplayr	413	sub eax, [ebx + TCP_SOCKET.ts_recent_age]
		414
		415	pop ecx
		416	cmp eax, TCP_PAWS_IDLE
5442	hidnplayr	417	jle .paws_drop
3545	hidnplayr	418	push ecx
		419	mov [ebx + TCP_SOCKET.ts_recent], 0 ; timestamp was invalid, fix it.
		420	.no_paws:
		421	jmp .opt_loop
		422
5442	hidnplayr	423	.paws_drop:
6476	hidnplayr	424	inc [TCPS_rcvduppack]
5442	hidnplayr	425	add [TCPS_rcvdupbyte], ecx
		426	inc [TCPS_pawsdrop]
		427	jmp .drop_after_ack
		428
3545	hidnplayr	429	.no_options:
		430
		431	pop ecx
		432
6476	hidnplayr	433	;-----------------------------------------------------------------------------------
		434	;
		435	; Header prediction
		436	;
		437	;-----------------------------------------------------------------------------------
3545	hidnplayr	438
6476	hidnplayr	439	; According to Van Jacobson, there are two common cases for an uni-directional data transfer.
3545	hidnplayr	440	;
		441	; General rule: the packets has no control flags, is in-sequence,
		442	; window width didnt change and we're not retransmitting.
		443	;
		444	; Second rules:
		445	; - If the length is 0 and the ACK moved forward, we're the sender side of the transfer.
		446	; In this case we'll free the ACK'ed data and notify higher levels that we have free space in buffer
		447	;
		448	; - If the length is not 0 and the ACK didn't move, we're the receiver side of the transfer.
		449	; If the packets are in order (data queue is empty), add the data to the socket buffer and request a delayed ACK
		450
		451	cmp [ebx + TCP_SOCKET.t_state], TCPS_ESTABLISHED
		452	jnz .not_uni_xfer
		453
		454	test [edx + TCP_header.Flags], TH_SYN + TH_FIN + TH_RST + TH_URG
		455	jnz .not_uni_xfer
		456
		457	test [edx + TCP_header.Flags], TH_ACK
		458	jz .not_uni_xfer
		459
		460	mov eax, [edx + TCP_header.SequenceNumber]
		461	cmp eax, [ebx + TCP_SOCKET.RCV_NXT]
		462	jne .not_uni_xfer
		463
6476	hidnplayr	464	mov eax, dword[edx + TCP_header.Window]
3545	hidnplayr	465	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		466	jne .not_uni_xfer
		467
		468	mov eax, [ebx + TCP_SOCKET.SND_NXT]
		469	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		470	jne .not_uni_xfer
		471
		472	;---------------------------------------
		473	; check if we are sender in the uni-xfer
		474
		475	; If the following 4 conditions are all true, this segment is a pure ACK.
		476	;
		477	; - The segment contains no data.
6476	hidnplayr	478
3545	hidnplayr	479	test ecx, ecx
		480	jnz .not_sender
		481
		482	; - The congestion window is greater than or equal to the current send window.
		483	; 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	484
3545	hidnplayr	485	mov eax, [ebx + TCP_SOCKET.SND_CWND]
		486	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		487	jb .not_uni_xfer
		488
		489	; - The acknowledgment field in the segment is less than or equal to the maximum sequence number sent.
6476	hidnplayr	490
3545	hidnplayr	491	mov eax, [edx + TCP_header.AckNumber]
		492	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		493	ja .not_uni_xfer
		494
		495	; - The acknowledgment field in the segment is greater than the largest unacknowledged sequence number.
6476	hidnplayr	496
3545	hidnplayr	497	sub eax, [ebx + TCP_SOCKET.SND_UNA]
		498	jbe .not_uni_xfer
		499
3556	hidnplayr	500	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Header prediction: we are sender\n"
3545	hidnplayr	501
		502	;---------------------------------
		503	; Packet is a pure ACK, process it
		504
6476	hidnplayr	505	inc [TCPS_predack]
		506
		507	inc [TCPS_rcvackpack]
		508	add [TCPS_rcvackbyte], eax
		509
3545	hidnplayr	510	; Delete acknowledged bytes from send buffer
6476	hidnplayr	511
3545	hidnplayr	512	pusha
		513	mov ecx, eax
		514	lea eax, [ebx + STREAM_SOCKET.snd]
6011	hidnplayr	515	call socket_ring_free
3545	hidnplayr	516	popa
		517
		518	; Update RTT estimators
		519
4347	hidnplayr	520	test [temp_bits], TCP_BIT_TIMESTAMP
3545	hidnplayr	521	jz .no_timestamp_rtt
4344	hidnplayr	522	mov eax, [timestamp]
3545	hidnplayr	523	sub eax, [ebx + TCP_SOCKET.ts_ecr]
		524	inc eax
6011	hidnplayr	525	call tcp_xmit_timer
3545	hidnplayr	526	jmp .rtt_done
5976	hidnplayr	527	.no_timestamp_rtt:
3545	hidnplayr	528
		529	cmp [ebx + TCP_SOCKET.t_rtt], 0
		530	je .rtt_done
		531	mov eax, [edx + TCP_header.AckNumber]
		532	cmp eax, [ebx + TCP_SOCKET.t_rtseq]
		533	jbe .rtt_done
		534	mov eax, [ebx + TCP_SOCKET.t_rtt]
6011	hidnplayr	535	call tcp_xmit_timer
3545	hidnplayr	536	.rtt_done:
		537
		538	; update window pointers
6476	hidnplayr	539
3545	hidnplayr	540	mov eax, [edx + TCP_header.AckNumber]
		541	mov [ebx + TCP_SOCKET.SND_UNA], eax
		542
		543	; Stop retransmit timer
6476	hidnplayr	544
3600	hidnplayr	545	and [ebx + TCP_SOCKET.timer_flags], not timer_flag_retransmission
3545	hidnplayr	546
		547	; Unlock the socket
6476	hidnplayr	548
3545	hidnplayr	549	pusha
		550	lea ecx, [ebx + SOCKET.mutex]
		551	call mutex_unlock
		552	popa
		553
		554	; Awaken waiting processes
6476	hidnplayr	555
3545	hidnplayr	556	mov eax, ebx
6011	hidnplayr	557	call socket_notify
3545	hidnplayr	558
		559	; Generate more output
6476	hidnplayr	560
6011	hidnplayr	561	call tcp_output
3545	hidnplayr	562
		563	jmp .drop_no_socket
		564
		565	;-------------------------------------------------
		566	; maybe we are the receiver in the uni-xfer then..
		567
		568	.not_sender:
6476	hidnplayr	569
3545	hidnplayr	570	; - The amount of data in the segment is greater than 0 (data count is in ecx)
6476	hidnplayr	571	; - The acknowledgment field equals the largest unacknowledged sequence number. This means no data is acknowledged by this segment.
3545	hidnplayr	572
		573	mov eax, [edx + TCP_header.AckNumber]
		574	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
		575	jne .not_uni_xfer
		576
5133	hidnplayr	577	; - The reassembly list of out-of-order segments for the connection is empty.
6476	hidnplayr	578
5133	hidnplayr	579	cmp [ebx + TCP_SOCKET.seg_next], 0
		580	jne .not_uni_xfer
3545	hidnplayr	581
		582	; Complete processing of received data
		583
3556	hidnplayr	584	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Header prediction: we are receiving %u bytes\n", ecx
3545	hidnplayr	585
4339	hidnplayr	586	mov esi, [dataoffset]
3545	hidnplayr	587	add esi, edx
		588	lea eax, [ebx + STREAM_SOCKET.rcv]
6011	hidnplayr	589	call socket_ring_write ; Add the data to the socket buffer
4344	hidnplayr	590	add [ebx + TCP_SOCKET.RCV_NXT], ecx ; Update sequence number with number of bytes we have copied
3545	hidnplayr	591
		592	mov eax, ebx
6011	hidnplayr	593	call socket_notify
3545	hidnplayr	594
		595	or [ebx + TCP_SOCKET.t_flags], TF_DELACK ; Set delayed ack flag
		596
		597	jmp .drop
		598
		599
6476	hidnplayr	600	;-----------------------------------------------------------------------------------
		601	;
		602	; TCP segment processing, the slow way
		603	;
		604	;-----------------------------------------------------------------------------------
		605
3545	hidnplayr	606	.not_uni_xfer:
3556	hidnplayr	607	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Header prediction failed\n"
3545	hidnplayr	608
		609	; Calculate receive window size
6476	hidnplayr	610
3545	hidnplayr	611	push edx
6413	hidnplayr	612	mov eax, SOCKET_BUFFER_SIZE
3545	hidnplayr	613	sub eax, [ebx + STREAM_SOCKET.rcv.size]
4366	hidnplayr	614	DEBUGF DEBUG_NETWORK_VERBOSE, "Space in receive buffer=%d\n", eax
3545	hidnplayr	615	mov edx, [ebx + TCP_SOCKET.RCV_ADV]
		616	sub edx, [ebx + TCP_SOCKET.RCV_NXT]
4366	hidnplayr	617	DEBUGF DEBUG_NETWORK_VERBOSE, "Current advertised window=%d\n", edx
3545	hidnplayr	618	cmp eax, edx
		619	jg @f
		620	mov eax, edx
		621	@@:
3556	hidnplayr	622	DEBUGF DEBUG_NETWORK_VERBOSE, "Receive window size=%d\n", eax
3545	hidnplayr	623	mov [ebx + TCP_SOCKET.RCV_WND], eax
		624	pop edx
		625
		626	; If we are in listen or syn_sent state, go to that specific code right away
		627
		628	cmp [ebx + TCP_SOCKET.t_state], TCPS_LISTEN
6476	hidnplayr	629	je .state_listen
3545	hidnplayr	630
		631	cmp [ebx + TCP_SOCKET.t_state], TCPS_SYN_SENT
6476	hidnplayr	632	je .state_syn_sent
3545	hidnplayr	633
6476	hidnplayr	634	;-----------------------------------------------------------------------------------
		635	;
		636	; Trim any data not in window
		637	;
		638	;-----------------------------------------------------------------------------------
3545	hidnplayr	639
6476	hidnplayr	640	;-------------------------------------------------
		641	; Check for duplicate data at beginning of segment
3545	hidnplayr	642
4339	hidnplayr	643	; Calculate number of bytes we need to drop
6476	hidnplayr	644
3545	hidnplayr	645	mov eax, [ebx + TCP_SOCKET.RCV_NXT]
		646	sub eax, [edx + TCP_header.SequenceNumber]
		647	jle .no_duplicate
		648
3556	hidnplayr	649	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: %u bytes duplicate data!\n", eax
3545	hidnplayr	650
6476	hidnplayr	651	; Check for duplicate SYN
		652
3545	hidnplayr	653	test [edx + TCP_header.Flags], TH_SYN
		654	jz .no_dup_syn
		655
3556	hidnplayr	656	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: got duplicate syn\n"
3545	hidnplayr	657
		658	and [edx + TCP_header.Flags], not (TH_SYN)
		659	inc [edx + TCP_header.SequenceNumber]
		660
		661	cmp [edx + TCP_header.UrgentPointer], 1
		662	jbe @f
		663	dec [edx + TCP_header.UrgentPointer]
		664	jmp .dup_syn
		665	@@:
		666	and [edx + TCP_header.Flags], not (TH_URG)
		667	.dup_syn:
		668	dec eax
		669	.no_dup_syn:
		670
6476	hidnplayr	671	;-----------------------------------
		672	; Check for entire duplicate segment
		673
3545	hidnplayr	674	cmp eax, ecx ; eax holds number of bytes to drop, ecx is data size
6476	hidnplayr	675	jb .no_complete_dup
3545	hidnplayr	676	jnz @f
		677	test [edx + TCP_header.Flags], TH_FIN
6476	hidnplayr	678	jnz .no_complete_dup
3545	hidnplayr	679	@@:
		680
		681	; Any valid FIN must be to the left of the window.
		682	; At this point the FIN must be out of sequence or a duplicate, drop it
6476	hidnplayr	683
3545	hidnplayr	684	and [edx + TCP_header.Flags], not TH_FIN
		685
6476	hidnplayr	686	; send an ACK to resynchronize and drop any data.
3545	hidnplayr	687	; But keep on processing for RST or ACK
6476	hidnplayr	688
3545	hidnplayr	689	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
		690	mov eax, ecx
		691
6476	hidnplayr	692	inc [TCPS_rcvduppack]
		693	add [TCPS_rcvdupbyte], eax
		694	jmp .dup_processed
		695	.no_complete_dup:
5442	hidnplayr	696	inc [TCPS_rcvpartduppack]
6476	hidnplayr	697	add [TCPS_rcvpartdupbyte], eax
		698	.dup_processed:
5442	hidnplayr	699
3545	hidnplayr	700	;-----------------------------------------------
		701	; Remove duplicate data and update urgent offset
		702
4387	hidnplayr	703	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: trimming duplicate data\n"
4339	hidnplayr	704
		705	; Trim data from left side of window
6476	hidnplayr	706
4339	hidnplayr	707	add [dataoffset], eax
3545	hidnplayr	708	add [edx + TCP_header.SequenceNumber], eax
		709	sub ecx, eax
		710
		711	sub [edx + TCP_header.UrgentPointer], ax
		712	jg @f
		713	and [edx + TCP_header.Flags], not (TH_URG)
		714	mov [edx + TCP_header.UrgentPointer], 0
		715	@@:
6476	hidnplayr	716	.no_duplicate:
3545	hidnplayr	717
		718	;--------------------------------------------------
4339	hidnplayr	719	; Handle data that arrives after process terminates
3545	hidnplayr	720
4339	hidnplayr	721	cmp [ebx + SOCKET.PID], 0 ;;; TODO: use socket flags instead??
3545	hidnplayr	722	jne .not_terminated
		723	cmp [ebx + TCP_SOCKET.t_state], TCPS_CLOSE_WAIT
		724	jbe .not_terminated
		725	test ecx, ecx
		726	jz .not_terminated
		727
		728	mov eax, ebx
6011	hidnplayr	729	call tcp_close
5442	hidnplayr	730	inc [TCPS_rcvafterclose]
3545	hidnplayr	731	jmp .respond_seg_reset
6476	hidnplayr	732	.not_terminated:
3545	hidnplayr	733
		734	;----------------------------------------
4339	hidnplayr	735	; Remove data beyond right edge of window
3545	hidnplayr	736
		737	mov eax, [edx + TCP_header.SequenceNumber]
		738	add eax, ecx
		739	sub eax, [ebx + TCP_SOCKET.RCV_NXT]
		740	sub eax, [ebx + TCP_SOCKET.RCV_WND] ; eax now holds the number of bytes to drop
		741	jle .no_excess_data
		742
3556	hidnplayr	743	DEBUGF DEBUG_NETWORK_VERBOSE, "%d bytes beyond right edge of window\n", eax
3545	hidnplayr	744
6476	hidnplayr	745	inc [TCPS_rcvpackafterwin]
		746
3545	hidnplayr	747	cmp eax, ecx
		748	jl .dont_drop_all
6476	hidnplayr	749
		750	add [TCPS_rcvbyteafterwin], ecx
		751
		752	;----------------------------------------------------------------------------------------------------
3545	hidnplayr	753	; If a new connection request is received while in TIME_WAIT, drop the old connection and start over,
		754	; if the sequence numbers are above the previous ones
		755
		756	test [edx + TCP_header.Flags], TH_SYN
		757	jz .no_new_request
6476	hidnplayr	758	cmp [ebx + TCP_SOCKET.t_state], TCPS_TIME_WAIT
3545	hidnplayr	759	jne .no_new_request
		760	; mov edx, [ebx + TCP_SOCKET.RCV_NXT]
		761	; cmp edx, [edx + TCP_header.SequenceNumber]
		762	; add edx, 64000 ; TCP_ISSINCR FIXME
		763	mov eax, ebx
6011	hidnplayr	764	call tcp_close
3545	hidnplayr	765	jmp .findpcb ; FIXME: skip code for unscaling window, ...
		766	.no_new_request:
		767
4339	hidnplayr	768	; If window is closed, we can only take segments at window edge, and have to drop data and PUSH from
3545	hidnplayr	769	; incoming segments. Continue processing, but remember to ACK. Otherwise drop segment and ACK
		770
		771	cmp [ebx + TCP_SOCKET.RCV_WND], 0
		772	jne .drop_after_ack
4339	hidnplayr	773	mov esi, [edx + TCP_header.SequenceNumber]
		774	cmp esi, [ebx + TCP_SOCKET.RCV_NXT]
3545	hidnplayr	775	jne .drop_after_ack
		776
		777	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
6476	hidnplayr	778	inc [TCPS_rcvwinprobe]
3545	hidnplayr	779	.dont_drop_all:
6476	hidnplayr	780	add [TCPS_rcvbyteafterwin], eax
4347	hidnplayr	781	DEBUGF DEBUG_NETWORK_VERBOSE, "Trimming %u bytes from the right of the window\n"
6476	hidnplayr	782
		783	; remove data from the right side of window (decrease data length)
		784
		785	sub ecx, eax
4347	hidnplayr	786	and [edx + TCP_header.Flags], not (TH_PUSH or TH_FIN)
3545	hidnplayr	787	.no_excess_data:
		788
6476	hidnplayr	789	;-----------------------------------------------------------------------------------
		790	;
4339	hidnplayr	791	; Record timestamp
6476	hidnplayr	792	;
		793	;-----------------------------------------------------------------------------------
3545	hidnplayr	794
		795	; If last ACK falls within this segments sequence numbers, record its timestamp
6476	hidnplayr	796
4347	hidnplayr	797	test [temp_bits], TCP_BIT_TIMESTAMP
3545	hidnplayr	798	jz .no_timestamp
		799	mov eax, [ebx + TCP_SOCKET.last_ack_sent]
		800	sub eax, [edx + TCP_header.SequenceNumber]
		801	jb .no_timestamp
6476	hidnplayr	802	test [edx + TCP_header.Flags], TH_SYN or TH_FIN ; SYN and FIN occupy one byte
3545	hidnplayr	803	jz @f
		804	dec eax
		805	@@:
		806	sub eax, ecx
		807	jae .no_timestamp
		808
3556	hidnplayr	809	DEBUGF DEBUG_NETWORK_VERBOSE, "Recording timestamp\n"
3545	hidnplayr	810
4344	hidnplayr	811	mov eax, [timestamp]
3545	hidnplayr	812	mov [ebx + TCP_SOCKET.ts_recent_age], eax
		813	mov eax, [ebx + TCP_SOCKET.ts_val]
		814	mov [ebx + TCP_SOCKET.ts_recent], eax
		815	.no_timestamp:
		816
6476	hidnplayr	817	;-----------------------------------------------------------------------------------
		818	;
		819	; Process RST flag
		820	;
		821	;-----------------------------------------------------------------------------------
3545	hidnplayr	822
		823	test [edx + TCP_header.Flags], TH_RST
		824	jz .no_rst
		825
3556	hidnplayr	826	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Got an RST flag\n"
3545	hidnplayr	827
		828	mov eax, [ebx + TCP_SOCKET.t_state]
		829	shl eax, 2
		830	jmp dword [eax + .rst_sw_list]
		831
6476	hidnplayr	832	;-----------------------------------------------------------------------------------
3545	hidnplayr	833	.rst_sw_list:
		834	dd .no_rst ; TCPS_CLOSED
		835	dd .no_rst ; TCPS_LISTEN
		836	dd .no_rst ; TCPS_SYN_SENT
		837	dd .econnrefused ; TCPS_SYN_RECEIVED
		838	dd .econnreset ; TCPS_ESTABLISHED
		839	dd .econnreset ; TCPS_CLOSE_WAIT
		840	dd .econnreset ; TCPS_FIN_WAIT_1
		841	dd .rst_close ; TCPS_CLOSING
		842	dd .rst_close ; TCPS_LAST_ACK
		843	dd .econnreset ; TCPS_FIN_WAIT_2
6476	hidnplayr	844	dd .rst_close ; TCPS_TIME_WAIT
3545	hidnplayr	845
6476	hidnplayr	846	;-----------------------------------------------------------------------------------
3545	hidnplayr	847	.econnrefused:
3556	hidnplayr	848	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Connection refused\n"
3545	hidnplayr	849	mov [ebx + SOCKET.errorcode], ECONNREFUSED
		850	jmp .close
		851
6476	hidnplayr	852	;-----------------------------------------------------------------------------------
3545	hidnplayr	853	.econnreset:
3556	hidnplayr	854	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Connection reset\n"
3545	hidnplayr	855	mov [ebx + SOCKET.errorcode], ECONNRESET
		856	.close:
3556	hidnplayr	857	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Closing connection\n"
6476	hidnplayr	858	mov [ebx + TCP_SOCKET.t_state], TCPS_CLOSED
		859	inc [TCPS_drops]
3545	hidnplayr	860
6476	hidnplayr	861
3545	hidnplayr	862	mov eax, ebx
6011	hidnplayr	863	call tcp_close
3545	hidnplayr	864	jmp .drop_no_socket
		865
6476	hidnplayr	866	;-----------------------------------------------------------------------------------
3545	hidnplayr	867	.rst_close:
3556	hidnplayr	868	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Closing with reset\n"
3545	hidnplayr	869
		870	mov eax, ebx
6011	hidnplayr	871	call tcp_close
3545	hidnplayr	872	jmp .drop_no_socket
		873
6476	hidnplayr	874	;-----------------------------------------------------------------------------------
3545	hidnplayr	875	.no_rst:
		876
6476	hidnplayr	877	;-----------------------------------------------------------------------------------
		878	;
		879	; Handle SYN-full and ACK-less segments
		880	;
		881	;-----------------------------------------------------------------------------------
3545	hidnplayr	882
6476	hidnplayr	883	; If a SYN is in the window, then this is an error so we send an RST and drop the connection
		884
3545	hidnplayr	885	test [edx + TCP_header.Flags], TH_SYN
		886	jz .not_syn_full
		887
		888	mov eax, ebx
		889	mov ebx, ECONNRESET
6011	hidnplayr	890	call tcp_drop
3545	hidnplayr	891	jmp .drop_with_reset
		892	.not_syn_full:
		893
6476	hidnplayr	894	; If ACK bit is off, we drop the segment and return
3545	hidnplayr	895
		896	test [edx + TCP_header.Flags], TH_ACK
		897	jz .drop
		898
6476	hidnplayr	899	;----------------------------------------------------------------------------------
		900	;
		901	; ACK processing for SYN_RECEIVED state
		902	;
		903	;----------------------------------------------------------------------------------
		904
3545	hidnplayr	905	cmp [ebx + TCP_SOCKET.t_state], TCPS_SYN_RECEIVED
		906	jb .ack_processed ; states: closed, listen, syn_sent
		907	ja .no_syn_rcv ; established, fin_wait_1, fin_wait_2, close_wait, closing, last_ack, time_wait
		908
3556	hidnplayr	909	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: state=syn_received\n"
3545	hidnplayr	910
		911	mov eax, [edx + TCP_header.AckNumber]
		912	cmp [ebx + TCP_SOCKET.SND_UNA], eax
		913	ja .drop_with_reset
		914	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		915	ja .drop_with_reset
		916
6476	hidnplayr	917	inc [TCPS_connects]
3545	hidnplayr	918
		919	mov eax, ebx
6011	hidnplayr	920	call socket_is_connected
3545	hidnplayr	921	mov [ebx + TCP_SOCKET.t_state], TCPS_ESTABLISHED
		922
		923	; Do window scaling?
		924
		925	test [ebx + TCP_SOCKET.t_flags], TF_RCVD_SCALE
		926	jz @f
		927	test [ebx + TCP_SOCKET.t_flags], TF_REQ_SCALE
		928	jz @f
		929
6476	hidnplayr	930	push word[ebx + TCP_SOCKET.requested_s_scale] ; Set send and receive scale factors to the received values
		931	pop word[ebx + TCP_SOCKET.SND_SCALE]
3545	hidnplayr	932	@@:
		933
6011	hidnplayr	934	call tcp_reassemble
3545	hidnplayr	935
		936	mov eax, [edx + TCP_header.SequenceNumber]
		937	dec eax
		938	mov [ebx + TCP_SOCKET.SND_WL1], eax
		939	.no_syn_rcv:
		940
6476	hidnplayr	941	;-----------------------------------------------------------------------------------
		942	;
		943	; ACK processing for SYN_RECEIVED state and higher
		944	;
		945	;-----------------------------------------------------------------------------------
		946
3545	hidnplayr	947	;-------------------------
6476	hidnplayr	948	; Check for duplicate ACKs
3545	hidnplayr	949
		950	mov eax, [edx + TCP_header.AckNumber]
		951	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
6476	hidnplayr	952	ja .dup_ack_complete
3545	hidnplayr	953
		954	test ecx, ecx
		955	jnz .reset_dupacks
		956
6476	hidnplayr	957	mov eax, dword[edx + TCP_header.Window]
3545	hidnplayr	958	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		959	jne .reset_dupacks
		960
6476	hidnplayr	961	inc [TCPS_rcvdupack]
3556	hidnplayr	962	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Processing duplicate ACK\n"
3545	hidnplayr	963
		964	; If we have outstanding data, other than a window probe, this is a completely duplicate ACK
		965	; (window info didnt change) The ACK is the biggest we've seen and we've seen exactly our rexmt threshold of them,
		966	; assume a packet has been dropped and retransmit it. Kludge snd_nxt & the congestion window so we send only this one packet.
		967
3600	hidnplayr	968	test [ebx + TCP_SOCKET.timer_flags], timer_flag_retransmission
6476	hidnplayr	969	jz .reset_dupacks
3545	hidnplayr	970
		971	mov eax, [edx + TCP_header.AckNumber]
		972	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
6476	hidnplayr	973	jne .reset_dupacks
3545	hidnplayr	974
6476	hidnplayr	975	; Increment dupplicat ACK counter
		976	; If it reaches the threshold, re-transmit the missing segment
3545	hidnplayr	977
		978	inc [ebx + TCP_SOCKET.t_dupacks]
		979	cmp [ebx + TCP_SOCKET.t_dupacks], TCP_re_xmit_thresh
6476	hidnplayr	980	jb .dup_ack_complete
		981	ja .another_lost
3545	hidnplayr	982
6476	hidnplayr	983	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Re-transmitting lost segment\n"
		984
3545	hidnplayr	985	push [ebx + TCP_SOCKET.SND_NXT] ; >>>>
		986
		987	mov eax, [ebx + TCP_SOCKET.SND_WND]
		988	cmp eax, [ebx + TCP_SOCKET.SND_CWND]
4296	hidnplayr	989	jbe @f
		990	mov eax, [ebx + TCP_SOCKET.SND_CWND]
		991	@@:
3545	hidnplayr	992	shr eax, 1
		993	push edx
		994	xor edx, edx
		995	div [ebx + TCP_SOCKET.t_maxseg]
		996	cmp eax, 2
		997	ja @f
		998	xor eax, eax
		999	mov al, 2
		1000	@@:
		1001	mul [ebx + TCP_SOCKET.t_maxseg]
		1002	pop edx
		1003	mov [ebx + TCP_SOCKET.SND_SSTHRESH], eax
		1004
3600	hidnplayr	1005	and [ebx + TCP_SOCKET.timer_flags], not timer_flag_retransmission ; turn off retransmission timer
3545	hidnplayr	1006	mov [ebx + TCP_SOCKET.t_rtt], 0
		1007	mov eax, [edx + TCP_header.AckNumber]
		1008	mov [ebx + TCP_SOCKET.SND_NXT], eax
		1009	mov eax, [ebx + TCP_SOCKET.t_maxseg]
		1010	mov [ebx + TCP_SOCKET.SND_CWND], eax
		1011
		1012	; Unlock the socket
6476	hidnplayr	1013
3545	hidnplayr	1014	push ebx
		1015	lea ecx, [ebx + SOCKET.mutex]
		1016	call mutex_unlock
		1017
		1018	; retransmit missing segment
6476	hidnplayr	1019
3545	hidnplayr	1020	mov eax, [esp]
6011	hidnplayr	1021	call tcp_output
3545	hidnplayr	1022
		1023	; Lock the socket again
6476	hidnplayr	1024
3545	hidnplayr	1025	mov ecx, [esp]
		1026	add ecx, SOCKET.mutex
		1027	call mutex_lock
3711	clevermous	1028	pop ebx
3545	hidnplayr	1029
		1030	; Continue processing
6476	hidnplayr	1031
3545	hidnplayr	1032	xor edx, edx
		1033	mov eax, [ebx + TCP_SOCKET.t_maxseg]
		1034	mul [ebx + TCP_SOCKET.t_dupacks]
		1035	add eax, [ebx + TCP_SOCKET.SND_SSTHRESH]
		1036	mov [ebx + TCP_SOCKET.SND_CWND], eax
		1037
		1038	pop eax ; <<<<
		1039	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		1040	jb @f
		1041	mov [ebx + TCP_SOCKET.SND_NXT], eax
		1042	@@:
		1043	jmp .drop
		1044
6476	hidnplayr	1045	.another_lost:
3556	hidnplayr	1046	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Increasing congestion window\n"
3545	hidnplayr	1047
		1048	mov eax, [ebx + TCP_SOCKET.t_maxseg]
		1049	add [ebx + TCP_SOCKET.SND_CWND], eax
		1050
		1051	; Unlock the socket
6476	hidnplayr	1052
3545	hidnplayr	1053	push ebx
		1054	lea ecx, [ebx + SOCKET.mutex]
		1055	call mutex_unlock
		1056
6476	hidnplayr	1057	; retransmit missing segment, again
		1058
3545	hidnplayr	1059	mov eax, [esp]
6011	hidnplayr	1060	call tcp_output
3545	hidnplayr	1061
		1062	; Lock the socket again
6476	hidnplayr	1063
3545	hidnplayr	1064	mov ecx, [esp]
		1065	add ecx, SOCKET.mutex
		1066	call mutex_lock
		1067	pop ebx
		1068
6476	hidnplayr	1069	; And drop the incoming segment
		1070
3545	hidnplayr	1071	jmp .drop
		1072
6476	hidnplayr	1073	.reset_dupacks: ; We got a new ACK, reset duplicate ACK counter
		1074	mov [ebx + TCP_SOCKET.t_dupacks], 0
		1075	jmp .ack_processed
3545	hidnplayr	1076
6476	hidnplayr	1077	.dup_ack_complete:
3545	hidnplayr	1078
		1079	;-------------------------------------------------
		1080	; If the congestion window was inflated to account
		1081	; for the other side's cached packets, retract it
		1082
		1083	mov eax, [ebx + TCP_SOCKET.SND_SSTHRESH]
		1084	cmp eax, [ebx + TCP_SOCKET.SND_CWND]
		1085	ja @f
		1086	cmp [ebx + TCP_SOCKET.t_dupacks], TCP_re_xmit_thresh
		1087	jbe @f
		1088	mov [ebx + TCP_SOCKET.SND_CWND], eax
		1089	@@:
		1090
		1091	mov [ebx + TCP_SOCKET.t_dupacks], 0
		1092
		1093	mov eax, [edx + TCP_header.AckNumber]
		1094	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		1095	jbe @f
5442	hidnplayr	1096	inc [TCPS_rcvacktoomuch]
3545	hidnplayr	1097	jmp .drop_after_ack
		1098	@@:
		1099
		1100	mov edi, [edx + TCP_header.AckNumber]
		1101	sub edi, [ebx + TCP_SOCKET.SND_UNA] ; now we got the number of acked bytes in edi
5442	hidnplayr	1102	inc [TCPS_rcvackpack]
		1103	add [TCPS_rcvackbyte], edi
3556	hidnplayr	1104	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: acceptable ACK for %u bytes\n", edi
3545	hidnplayr	1105
6476	hidnplayr	1106	;-----------------------------------------------------------------------------------
		1107	;
4347	hidnplayr	1108	; RTT measurements and retransmission timer
6476	hidnplayr	1109	;
		1110	;-----------------------------------------------------------------------------------
3545	hidnplayr	1111
		1112	; If we have a timestamp, update smoothed RTT
		1113
4347	hidnplayr	1114	test [temp_bits], TCP_BIT_TIMESTAMP
3545	hidnplayr	1115	jz .timestamp_not_present
4344	hidnplayr	1116	mov eax, [timestamp]
3545	hidnplayr	1117	sub eax, [ebx + TCP_SOCKET.ts_ecr]
		1118	inc eax
6011	hidnplayr	1119	call tcp_xmit_timer
3545	hidnplayr	1120	jmp .rtt_done_
		1121
		1122	; If no timestamp but transmit timer is running and timed sequence number was acked,
		1123	; update smoothed RTT. Since we now have an RTT measurement, cancel the timer backoff
		1124	; (Phil Karn's retransmit algo)
		1125	; Recompute the initial retransmit timer
		1126
		1127	.timestamp_not_present:
		1128	mov eax, [edx + TCP_header.AckNumber]
		1129	cmp eax, [ebx + TCP_SOCKET.t_rtseq]
		1130	jbe .rtt_done_
		1131	mov eax, [ebx + TCP_SOCKET.t_rtt]
		1132	test eax, eax
		1133	jz .rtt_done_
6011	hidnplayr	1134	call tcp_xmit_timer
3545	hidnplayr	1135	.rtt_done_:
		1136
		1137	; If all outstanding data is acked, stop retransmit timer and remember to restart (more output or persist)
		1138	; If there is more data to be acked, restart retransmit timer, using current (possible backed-off) value.
		1139
		1140	mov eax, [ebx + TCP_SOCKET.SND_MAX]
		1141	cmp eax, [edx + TCP_header.AckNumber]
		1142	jne .more_data
3600	hidnplayr	1143	and [ebx + TCP_SOCKET.timer_flags], not timer_flag_retransmission
4347	hidnplayr	1144	or [temp_bits], TCP_BIT_NEEDOUTPUT
3545	hidnplayr	1145	jmp .no_restart
		1146	.more_data:
3600	hidnplayr	1147	test [ebx + TCP_SOCKET.timer_flags], timer_flag_persist
		1148	jnz .no_restart
3545	hidnplayr	1149
		1150	mov eax, [ebx + TCP_SOCKET.t_rxtcur]
		1151	mov [ebx + TCP_SOCKET.timer_retransmission], eax
3600	hidnplayr	1152	or [ebx + TCP_SOCKET.timer_flags], timer_flag_retransmission
3545	hidnplayr	1153	.no_restart:
		1154
6476	hidnplayr	1155	;-----------------------------------------------------------------------------------
		1156	;
3545	hidnplayr	1157	; Open congestion window in response to ACKs
6476	hidnplayr	1158	;
		1159	;-----------------------------------------------------------------------------------
3545	hidnplayr	1160
6476	hidnplayr	1161	; If the window gives us less then sstresh packets in flight, open exponentially.
		1162	; Otherwise, open lineary
		1163
3545	hidnplayr	1164	mov esi, [ebx + TCP_SOCKET.SND_CWND]
		1165	mov eax, [ebx + TCP_SOCKET.t_maxseg]
		1166	cmp esi, [ebx + TCP_SOCKET.SND_SSTHRESH]
		1167	jbe @f
		1168	push edx
		1169	push eax
6476	hidnplayr	1170	mul eax ; t_maxseg*t_maxseg
		1171	div esi ; t_maxseg*t_maxseg/snd_cwnd
		1172	pop edx ; t_maxseg
		1173	shr edx, 3 ; t_maxseg/8
		1174	add eax, edx ; t_maxseg*t_maxseg/snd_cwnd + t_maxseg/8
3545	hidnplayr	1175	pop edx
		1176	@@:
		1177	add esi, eax
		1178
		1179	push ecx
		1180	mov cl, [ebx + TCP_SOCKET.SND_SCALE]
		1181	mov eax, TCP_max_win
		1182	shl eax, cl
		1183	pop ecx
		1184
		1185	cmp esi, eax
4296	hidnplayr	1186	jbe @f
		1187	mov esi, eax
		1188	@@:
3545	hidnplayr	1189	mov [ebx + TCP_SOCKET.SND_CWND], esi
		1190
6476	hidnplayr	1191	;-----------------------------------------------------------------------------------
		1192	;
3545	hidnplayr	1193	; Remove acknowledged data from send buffer
6476	hidnplayr	1194	;
		1195	;-----------------------------------------------------------------------------------
3545	hidnplayr	1196
6476	hidnplayr	1197	; If the number of bytes acknowledged exceeds the number of bytes on the send buffer,
		1198	; snd_wnd is decremented by the number of bytes in the send buffer and TCP knows
		1199	; that its FIN has been ACKed. (FIN occupies 1 byte in the sequence number space)
		1200
3545	hidnplayr	1201	cmp edi, [ebx + STREAM_SOCKET.snd.size]
6476	hidnplayr	1202	jbe .no_fin_ack
3545	hidnplayr	1203
6476	hidnplayr	1204	; Drop all data in output buffer
		1205
3545	hidnplayr	1206	push ecx edx ebx
		1207	mov ecx, [ebx + STREAM_SOCKET.snd.size]
6476	hidnplayr	1208	sub [ebx + TCP_SOCKET.SND_WND], ecx
3545	hidnplayr	1209	lea eax, [ebx + STREAM_SOCKET.snd]
6011	hidnplayr	1210	call socket_ring_free
3545	hidnplayr	1211	pop ebx edx ecx
		1212
3556	hidnplayr	1213	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: our FIN is acked\n"
5133	hidnplayr	1214	or [temp_bits], TCP_BIT_FIN_IS_ACKED
6476	hidnplayr	1215	jmp .ack_complete
		1216	.no_fin_ack:
3545	hidnplayr	1217
6476	hidnplayr	1218	; Drop acknowledged data
3545	hidnplayr	1219
		1220	push ecx edx ebx
		1221	mov ecx, edi
		1222	lea eax, [ebx + STREAM_SOCKET.snd]
6011	hidnplayr	1223	call socket_ring_free
3545	hidnplayr	1224	pop ebx
		1225	sub [ebx + TCP_SOCKET.SND_WND], ecx
		1226	pop edx ecx
6476	hidnplayr	1227	.ack_complete:
3545	hidnplayr	1228
6476	hidnplayr	1229	;-----------------------------------------------------------------------------------
		1230	;
3545	hidnplayr	1231	; Wake up process waiting on send buffer
6476	hidnplayr	1232	;
		1233	;-----------------------------------------------------------------------------------
3545	hidnplayr	1234
		1235	mov eax, ebx
6011	hidnplayr	1236	call socket_notify
3545	hidnplayr	1237
		1238	; Update TCPS
6476	hidnplayr	1239
3545	hidnplayr	1240	mov eax, [edx + TCP_header.AckNumber]
		1241	mov [ebx + TCP_SOCKET.SND_UNA], eax
		1242	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		1243	jb @f
		1244	mov [ebx + TCP_SOCKET.SND_NXT], eax
		1245	@@:
		1246
6476	hidnplayr	1247	;-----------------------------------------------------------------------------------
		1248	;
		1249	; State specific ACK handeling
		1250	;
		1251	;-----------------------------------------------------------------------------------
3545	hidnplayr	1252
		1253	mov eax, [ebx + TCP_SOCKET.t_state]
6476	hidnplayr	1254	jmp dword[.ack_sw_list+eax*4]
3545	hidnplayr	1255
6476	hidnplayr	1256	.ack_sw_list:
3545	hidnplayr	1257	dd .ack_processed ; TCPS_CLOSED
		1258	dd .ack_processed ; TCPS_LISTEN
		1259	dd .ack_processed ; TCPS_SYN_SENT
		1260	dd .ack_processed ; TCPS_SYN_RECEIVED
		1261	dd .ack_processed ; TCPS_ESTABLISHED
		1262	dd .ack_processed ; TCPS_CLOSE_WAIT
		1263	dd .ack_fw1 ; TCPS_FIN_WAIT_1
		1264	dd .ack_c ; TCPS_CLOSING
		1265	dd .ack_la ; TCPS_LAST_ACK
		1266	dd .ack_processed ; TCPS_FIN_WAIT_2
		1267	dd .ack_tw ; TCPS_TIMED_WAIT
		1268
6476	hidnplayr	1269	;-----------------------------------------------------------------------------------
		1270	.ack_fw1:
		1271	; If our FIN is now acked, enter FIN_WAIT_2
3545	hidnplayr	1272
5133	hidnplayr	1273	test [temp_bits], TCP_BIT_FIN_IS_ACKED
		1274	jz .ack_processed
3545	hidnplayr	1275
6476	hidnplayr	1276	; If we can't receive any more data, then closing user can proceed.
		1277	; Starting the timer is contrary to the specification, but if we dont get a FIN,
		1278	; we'll hang forever.
		1279
3545	hidnplayr	1280	test [ebx + SOCKET.state], SS_CANTRCVMORE
		1281	jnz @f
		1282	mov eax, ebx
6011	hidnplayr	1283	call socket_is_disconnected
3545	hidnplayr	1284	mov [ebx + TCP_SOCKET.timer_timed_wait], TCP_time_max_idle
3600	hidnplayr	1285	or [ebx + TCP_SOCKET.timer_flags], timer_flag_wait
3545	hidnplayr	1286	@@:
		1287	mov [ebx + TCP_SOCKET.t_state], TCPS_FIN_WAIT_2
		1288	jmp .ack_processed
		1289
6476	hidnplayr	1290	;-----------------------------------------------------------------------------------
3545	hidnplayr	1291	.ack_c:
6476	hidnplayr	1292	; Enter the TIME_WAIT state if our FIN is acked in CLOSED state.
		1293
5133	hidnplayr	1294	test [temp_bits], TCP_BIT_FIN_IS_ACKED
		1295	jz .ack_processed
3545	hidnplayr	1296
6476	hidnplayr	1297	mov [ebx + TCP_SOCKET.t_state], TCPS_TIME_WAIT
3545	hidnplayr	1298	mov eax, ebx
6011	hidnplayr	1299	call tcp_cancel_timers
3545	hidnplayr	1300	mov [ebx + TCP_SOCKET.timer_timed_wait], 2 * TCP_time_MSL
3600	hidnplayr	1301	or [ebx + TCP_SOCKET.timer_flags], timer_flag_wait
3545	hidnplayr	1302	mov eax, ebx
6011	hidnplayr	1303	call socket_is_disconnected
3545	hidnplayr	1304	jmp .ack_processed
		1305
6476	hidnplayr	1306	;-----------------------------------------------------------------------------------
3545	hidnplayr	1307	.ack_la:
6476	hidnplayr	1308	; In LAST_ACK state, we may still be waiting for data to drain and/or to be acked.
		1309	; If our FIN is acked however, enter CLOSED state and return.
		1310
5133	hidnplayr	1311	test [temp_bits], TCP_BIT_FIN_IS_ACKED
		1312	jz .ack_processed
3545	hidnplayr	1313
3652	hidnplayr	1314	push ebx
		1315	lea ecx, [ebx + SOCKET.mutex]
		1316	call mutex_unlock
6476	hidnplayr	1317	pop eax
3652	hidnplayr	1318
6011	hidnplayr	1319	call tcp_close
4366	hidnplayr	1320	jmp .drop_no_socket
3545	hidnplayr	1321
6476	hidnplayr	1322	;-----------------------------------------------------------------------------------
3545	hidnplayr	1323	.ack_tw:
6476	hidnplayr	1324	; In TIME_WAIT state the only thing that should arrive is a retransmission of the remote FIN.
		1325	; Acknowledge it and restart the FINACK timer
		1326
		1327	mov [ebx + TCP_SOCKET.timer_timed_wait], 2*TCP_time_MSL
		1328	or [ebx + TCP_SOCKET.timer_flags], timer_flag_2msl
3545	hidnplayr	1329	jmp .drop_after_ack
		1330
6476	hidnplayr	1331	;-----------------------------------------------------------------------------------
		1332	;
		1333	; Initiation of Passive Open?
		1334	;
		1335	;-----------------------------------------------------------------------------------
3545	hidnplayr	1336
6476	hidnplayr	1337	.state_listen:
3556	hidnplayr	1338	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: state=listen\n"
3545	hidnplayr	1339
		1340	test [edx + TCP_header.Flags], TH_RST
		1341	jnz .drop
		1342
		1343	test [edx + TCP_header.Flags], TH_ACK
		1344	jnz .drop_with_reset
		1345
		1346	test [edx + TCP_header.Flags], TH_SYN
		1347	jz .drop
		1348
6476	hidnplayr	1349	inc [TCPS_accepts]
5442	hidnplayr	1350
3545	hidnplayr	1351	;;; TODO: check if it's a broadcast or multicast, and drop if so
		1352
6476	hidnplayr	1353	;-------------------------------------------
		1354	; Processing of SYN received in LISTEN state
		1355
5842	hidnplayr	1356	push [edi + IPv4_header.SourceAddress]
3545	hidnplayr	1357	pop [ebx + IP_SOCKET.RemoteIP]
		1358
		1359	push [edx + TCP_header.SourcePort]
		1360	pop [ebx + TCP_SOCKET.RemotePort]
		1361
		1362	push [edx + TCP_header.SequenceNumber]
		1363	pop [ebx + TCP_SOCKET.IRS]
		1364
		1365	mov eax, [TCP_sequence_num]
6476	hidnplayr	1366	add [TCP_sequence_num], TCP_ISSINCR / 2
3545	hidnplayr	1367	mov [ebx + TCP_SOCKET.ISS], eax
		1368	mov [ebx + TCP_SOCKET.SND_NXT], eax
		1369
6011	hidnplayr	1370	tcp_sendseqinit ebx
		1371	tcp_rcvseqinit ebx
3545	hidnplayr	1372
		1373	mov [ebx + TCP_SOCKET.t_state], TCPS_SYN_RECEIVED
4347	hidnplayr	1374	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
3545	hidnplayr	1375	mov [ebx + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval ;;;; macro
3600	hidnplayr	1376	or [ebx + TCP_SOCKET.timer_flags], timer_flag_keepalive
3545	hidnplayr	1377
		1378	lea eax, [ebx + STREAM_SOCKET.snd]
6011	hidnplayr	1379	call socket_ring_create
5155	hidnplayr	1380	test eax, eax
		1381	jz .drop
3545	hidnplayr	1382
		1383	lea eax, [ebx + STREAM_SOCKET.rcv]
6011	hidnplayr	1384	call socket_ring_create
5155	hidnplayr	1385	test eax, eax
		1386	jz .drop
3545	hidnplayr	1387
4347	hidnplayr	1388	and [temp_bits], not TCP_BIT_DROPSOCKET
3545	hidnplayr	1389
3674	hidnplayr	1390	pusha
		1391	mov eax, ebx
6011	hidnplayr	1392	call socket_notify
3674	hidnplayr	1393	popa
3545	hidnplayr	1394
5133	hidnplayr	1395	jmp .trim
3545	hidnplayr	1396
6476	hidnplayr	1397	;-----------------------------------------------------------------------------------
		1398	;
		1399	; Completion of active open?
		1400	;
		1401	;-----------------------------------------------------------------------------------
3545	hidnplayr	1402
6476	hidnplayr	1403	.state_syn_sent:
3556	hidnplayr	1404	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: state=syn_sent\n"
3545	hidnplayr	1405
		1406	test [edx + TCP_header.Flags], TH_ACK
		1407	jz @f
		1408
		1409	mov eax, [edx + TCP_header.AckNumber]
		1410	cmp eax, [ebx + TCP_SOCKET.ISS]
		1411	jbe .drop_with_reset
		1412
		1413	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		1414	ja .drop_with_reset
		1415	@@:
		1416
		1417	test [edx + TCP_header.Flags], TH_RST
		1418	jz @f
		1419
		1420	test [edx + TCP_header.Flags], TH_ACK
		1421	jz .drop
		1422
		1423	mov eax, ebx
		1424	mov ebx, ECONNREFUSED
6011	hidnplayr	1425	call tcp_drop
3545	hidnplayr	1426	jmp .drop
		1427	@@:
		1428
6476	hidnplayr	1429	;-----------------------------------------------------------------------------------
		1430	;
		1431	; Process received SYN in response to an active open
		1432	;
		1433	;-----------------------------------------------------------------------------------
		1434
3545	hidnplayr	1435	test [edx + TCP_header.Flags], TH_SYN
		1436	jz .drop
		1437
		1438	test [edx + TCP_header.Flags], TH_ACK
6476	hidnplayr	1439	jz @f
3545	hidnplayr	1440
		1441	mov eax, [edx + TCP_header.AckNumber]
		1442	mov [ebx + TCP_SOCKET.SND_UNA], eax
		1443	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		1444	jbe @f
		1445	mov [ebx + TCP_SOCKET.SND_NXT], eax
		1446
3600	hidnplayr	1447	and [ebx + TCP_SOCKET.timer_flags], not timer_flag_retransmission ; disable retransmission timer
6476	hidnplayr	1448	@@:
3545	hidnplayr	1449
		1450	push [edx + TCP_header.SequenceNumber]
		1451	pop [ebx + TCP_SOCKET.IRS]
		1452
6011	hidnplayr	1453	tcp_rcvseqinit ebx
3545	hidnplayr	1454
		1455	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
		1456
		1457	mov eax, [ebx + TCP_SOCKET.SND_UNA]
		1458	cmp eax, [ebx + TCP_SOCKET.ISS]
		1459	jbe .simultaneous_open
		1460
		1461	test [edx + TCP_header.Flags], TH_ACK
		1462	jz .simultaneous_open
		1463
3556	hidnplayr	1464	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: active open\n"
3545	hidnplayr	1465
6476	hidnplayr	1466	inc [TCPS_connects]
3545	hidnplayr	1467
		1468	; set socket state to connected
6476	hidnplayr	1469
3674	hidnplayr	1470	push eax
		1471	mov eax, ebx
6011	hidnplayr	1472	call socket_is_connected
3674	hidnplayr	1473	pop eax
3545	hidnplayr	1474	mov [ebx + TCP_SOCKET.t_state], TCPS_ESTABLISHED
		1475
		1476	; Do window scaling on this connection ?
6476	hidnplayr	1477
3545	hidnplayr	1478	mov eax, [ebx + TCP_SOCKET.t_flags]
		1479	and eax, TF_REQ_SCALE or TF_RCVD_SCALE
		1480	cmp eax, TF_REQ_SCALE or TF_RCVD_SCALE
		1481	jne .no_scaling
		1482
6011	hidnplayr	1483	mov ax, word[ebx + TCP_SOCKET.requested_s_scale]
		1484	mov word[ebx + TCP_SOCKET.SND_SCALE], ax
3545	hidnplayr	1485	.no_scaling:
		1486
		1487	;;; TODO: reassemble packets queue
		1488
6476	hidnplayr	1489	; If we didnt have time to re-transmit the SYN,
		1490	; Use its rtt as our initial srtt & rtt var.
		1491
3545	hidnplayr	1492	mov eax, [ebx + TCP_SOCKET.t_rtt]
		1493	test eax, eax
5133	hidnplayr	1494	je .trim
6011	hidnplayr	1495	call tcp_xmit_timer
5133	hidnplayr	1496	jmp .trim
3545	hidnplayr	1497
6476	hidnplayr	1498	;-----------------------------------------------------------------------------------
		1499	;
		1500	; Simultaneous open (We have received a SYN but no ACK)
		1501	;
		1502	;-----------------------------------------------------------------------------------
		1503
3545	hidnplayr	1504	.simultaneous_open:
3556	hidnplayr	1505	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: simultaneous open\n"
3545	hidnplayr	1506	mov [ebx + TCP_SOCKET.t_state], TCPS_SYN_RECEIVED
		1507
6476	hidnplayr	1508	;-----------------------------------------------------------------------------------
		1509	;
3545	hidnplayr	1510	; Common processing for receipt of SYN
6476	hidnplayr	1511	;
		1512	;-----------------------------------------------------------------------------------
3545	hidnplayr	1513
5133	hidnplayr	1514	.trim:
6476	hidnplayr	1515	; Advance sequence number to correspond to first data byte.
		1516	; If data, trim to stay within window, dropping FIN if necessary
		1517
3545	hidnplayr	1518	inc [edx + TCP_header.SequenceNumber]
		1519
4339	hidnplayr	1520	; Drop any received data that doesnt fit in the receive window.
6476	hidnplayr	1521
4339	hidnplayr	1522	cmp ecx, [ebx + TCP_SOCKET.RCV_WND]
		1523	jbe .dont_trim
3545	hidnplayr	1524
4339	hidnplayr	1525	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: received data does not fit in window, trimming %u bytes\n", eax
6476	hidnplayr	1526	inc [TCPS_rcvpackafterwin]
		1527	sub ecx, [ebx + TCP_SOCKET.RCV_WND]
		1528	add [TCPS_rcvbyteafterwin], ecx
		1529
		1530	and [edx + TCP_header.Flags], not (TH_FIN)
4339	hidnplayr	1531	mov ecx, [ebx + TCP_SOCKET.RCV_WND]
		1532
		1533	.dont_trim:
3545	hidnplayr	1534	mov eax, [edx + TCP_header.SequenceNumber]
		1535	mov [ebx + TCP_SOCKET.RCV_UP], eax
		1536	dec eax
		1537	mov [ebx + TCP_SOCKET.SND_WL1], eax
		1538
6476	hidnplayr	1539	;-----------------------------------------------------------------------------------
		1540	;
		1541	; Update window information (step 6 in RFC793)
		1542	;
		1543	;-----------------------------------------------------------------------------------
		1544
3545	hidnplayr	1545	.ack_processed:
3556	hidnplayr	1546	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: ACK processed\n"
3545	hidnplayr	1547
6476	hidnplayr	1548	; dont look at window if no ACK
3545	hidnplayr	1549
		1550	test [edx + TCP_header.Flags], TH_ACK
		1551	jz .no_window_update
		1552
6476	hidnplayr	1553	; Does the segment contain new data?
		1554
3545	hidnplayr	1555	mov eax, [ebx + TCP_SOCKET.SND_WL1]
		1556	cmp eax, [edx + TCP_header.SequenceNumber]
		1557	jb .update_window
		1558	ja @f
		1559
6476	hidnplayr	1560	; No new data but a new ACK ?
		1561
3545	hidnplayr	1562	mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1563	cmp eax, [edx + TCP_header.AckNumber]
		1564	jb .update_window
		1565	@@:
		1566
6476	hidnplayr	1567	; No new data or ACK but advertised window is larger then current window?
		1568
		1569	mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1570	cmp eax, [edx + TCP_header.AckNumber]
		1571	jne .no_window_update
		1572
		1573	mov eax, dword[edx + TCP_header.Window]
3545	hidnplayr	1574	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		1575	jbe .no_window_update
		1576
6476	hidnplayr	1577
		1578	; Keep track of pure window updates
3545	hidnplayr	1579	.update_window:
6476	hidnplayr	1580	test ecx, ecx
		1581	jnz @f
		1582	mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1583	cmp eax, [edx + TCP_header.AckNumber]
		1584	jne @f
		1585	mov eax, dword[edx + TCP_header.Window]
		1586	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		1587	jbe @f
		1588	inc [TCPS_rcvwinupd]
		1589	@@:
3545	hidnplayr	1590
6476	hidnplayr	1591	mov eax, dword[edx + TCP_header.Window]
		1592	mov [ebx + TCP_SOCKET.SND_WND], eax
3545	hidnplayr	1593	cmp eax, [ebx + TCP_SOCKET.max_sndwnd]
		1594	jbe @f
		1595	mov [ebx + TCP_SOCKET.max_sndwnd], eax
		1596	@@:
		1597
3556	hidnplayr	1598	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Updating window to %u\n", eax
3545	hidnplayr	1599
		1600	push [edx + TCP_header.SequenceNumber]
		1601	pop [ebx + TCP_SOCKET.SND_WL1]
		1602
		1603	push [edx + TCP_header.AckNumber]
		1604	pop [ebx + TCP_SOCKET.SND_WL2]
		1605
4347	hidnplayr	1606	or [temp_bits], TCP_BIT_NEEDOUTPUT
3545	hidnplayr	1607	.no_window_update:
		1608
6476	hidnplayr	1609	;-----------------------------------------------------------------------------------
		1610	;
		1611	; Process URG flag
		1612	;
		1613	;-----------------------------------------------------------------------------------
3545	hidnplayr	1614
		1615	test [edx + TCP_header.Flags], TH_URG
		1616	jz .not_urgent
		1617
		1618	cmp [edx + TCP_header.UrgentPointer], 0
		1619	jz .not_urgent
		1620
6476	hidnplayr	1621	cmp [ebx + TCP_SOCKET.t_state], TCPS_TIME_WAIT
3545	hidnplayr	1622	je .not_urgent
		1623
		1624	; Ignore bogus urgent offsets
		1625
		1626	movzx eax, [edx + TCP_header.UrgentPointer]
		1627	add eax, [ebx + STREAM_SOCKET.rcv.size]
6413	hidnplayr	1628	cmp eax, SOCKET_BUFFER_SIZE
3545	hidnplayr	1629	jbe .not_urgent
		1630
		1631	mov [edx + TCP_header.UrgentPointer], 0
		1632	and [edx + TCP_header.Flags], not (TH_URG)
		1633	jmp .do_data
		1634
		1635	.not_urgent:
		1636
		1637	; processing of received urgent pointer
		1638
		1639	;;; TODO (1051-1093)
		1640
6476	hidnplayr	1641	;-----------------------------------------------------------------------------------
		1642	;
		1643	; Process the data
		1644	;
		1645	;-----------------------------------------------------------------------------------
3545	hidnplayr	1646
		1647	.do_data:
6476	hidnplayr	1648	cmp [ebx + TCP_SOCKET.t_state], TCPS_TIME_WAIT
3545	hidnplayr	1649	jae .final_processing
		1650
		1651	test [edx + TCP_header.Flags], TH_FIN
		1652	jnz @f
		1653
		1654	test ecx, ecx
3756	hidnplayr	1655	jz .final_processing
3545	hidnplayr	1656	@@:
		1657
		1658	; The segment is in order?
6476	hidnplayr	1659
3545	hidnplayr	1660	mov eax, [edx + TCP_header.SequenceNumber]
		1661	cmp eax, [ebx + TCP_SOCKET.RCV_NXT]
		1662	jne .out_of_order
		1663
		1664	; The reassembly queue is empty?
6476	hidnplayr	1665
3545	hidnplayr	1666	cmp [ebx + TCP_SOCKET.seg_next], 0
		1667	jne .out_of_order
		1668
		1669	; The connection is established?
6476	hidnplayr	1670
3545	hidnplayr	1671	cmp [ebx + TCP_SOCKET.t_state], TCPS_ESTABLISHED
		1672	jne .out_of_order
		1673
		1674	; Ok, lets do this.. Set delayed ACK flag and copy data into socket buffer
6476	hidnplayr	1675
3545	hidnplayr	1676	or [ebx + TCP_SOCKET.t_flags], TF_DELACK
		1677
		1678	pusha
4339	hidnplayr	1679	mov esi, [dataoffset]
3545	hidnplayr	1680	add esi, edx
		1681	lea eax, [ebx + STREAM_SOCKET.rcv]
6011	hidnplayr	1682	call socket_ring_write ; Add the data to the socket buffer
3545	hidnplayr	1683	add [ebx + TCP_SOCKET.RCV_NXT], ecx ; Update sequence number with number of bytes we have copied
		1684	popa
		1685
		1686	; Wake up the sleeping process
6476	hidnplayr	1687
3545	hidnplayr	1688	mov eax, ebx
6011	hidnplayr	1689	call socket_notify
3545	hidnplayr	1690
		1691	jmp .data_done
		1692
		1693	.out_of_order:
4339	hidnplayr	1694	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP data is out of order!\nSequencenumber is %u, we expected %u.\n", \
		1695	[edx + TCP_header.SequenceNumber], [ebx + TCP_SOCKET.RCV_NXT]
3545	hidnplayr	1696
		1697	; Uh-oh, some data is out of order, lets call TCP reassemble for help
		1698
6011	hidnplayr	1699	call tcp_reassemble
3545	hidnplayr	1700
4339	hidnplayr	1701	; Generate ACK immediately, to let the other end know that a segment was received out of order,
		1702	; and to tell it what sequence number is expected. This aids the fast-retransmit algorithm.
6476	hidnplayr	1703
3545	hidnplayr	1704	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
		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
3556	hidnplayr	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
3556	hidnplayr	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:
		1782	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Final processing\n"
		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
4347	hidnplayr	1794	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: ACK now!\n"
		1795
		1796	.need_output:
		1797	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: need output\n"
6011	hidnplayr	1798	call tcp_output
4347	hidnplayr	1799
5133	hidnplayr	1800	.done:
4347	hidnplayr	1801	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: dumping\n"
		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:
3556	hidnplayr	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:
3556	hidnplayr	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
5842	hidnplayr	1887	xor ebx, ebx ; FIXME: find a way to get the receiving device ptr
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
5842	hidnplayr	1893	xor ebx, ebx ; FIXME: find a way to get the receiving device ptr
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:
3556	hidnplayr	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:
3556	hidnplayr	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 6476