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: 6908 $
3545	hidnplayr	18
6476	hidnplayr	19	TCP_BIT_NEEDOUTPUT = 1 shl 0
		20	TCP_BIT_TIMESTAMP = 1 shl 1
		21	TCP_BIT_DROPSOCKET = 1 shl 2
		22	TCP_BIT_FIN_IS_ACKED = 1 shl 3
		23
5976	hidnplayr	24	;-----------------------------------------------------------------;
		25	; ;
		26	; TCP_input: Add a segment to the incoming TCP queue. ;
		27	; ;
		28	; IN: [esp] = ptr to buffer ;
		29	; ebx = ptr to device struct ;
		30	; ecx = TCP segment size ;
		31	; edx = ptr to IPv4 header ;
		32	; esi = ptr to TCP segment ;
		33	; edi = interface number*4 ;
		34	; ;
		35	; OUT: / ;
		36	; ;
		37	;-----------------------------------------------------------------;
3545	hidnplayr	38	align 4
6011	hidnplayr	39	tcp_input:
6908	ashmew2	40
3545	hidnplayr	41	; record the current time
5522	hidnplayr	42	push [timer_ticks] ; in 1/100 seconds
5842	hidnplayr	43	push ebx ecx esi edx ; mind the order (see TCP_queue_entry struct)
3545	hidnplayr	44	mov esi, esp
		45
5842	hidnplayr	46	push edi
3545	hidnplayr	47	add_to_queue TCP_queue, TCP_QUEUE_SIZE, sizeof.TCP_queue_entry, .fail
5842	hidnplayr	48	pop edi
3545	hidnplayr	49	add esp, sizeof.TCP_queue_entry
		50
3644	hidnplayr	51	inc [TCP_segments_rx + edi]
		52
3545	hidnplayr	53	xor edx, edx
		54	mov eax, [TCP_input_event]
		55	mov ebx, [eax + EVENT.id]
		56	xor esi, esi
		57	call raise_event
		58
		59	ret
		60
		61	.fail:
5842	hidnplayr	62	pop edi
3556	hidnplayr	63	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP incoming queue is full, discarding packet!\n"
3545	hidnplayr	64
6011	hidnplayr	65	call net_ptr_to_num4
3644	hidnplayr	66	inc [TCP_segments_missed + edi]
3545	hidnplayr	67
5841	hidnplayr	68	add esp, sizeof.TCP_queue_entry - 4
6011	hidnplayr	69	call net_buff_free
3545	hidnplayr	70	ret
		71
		72
6476	hidnplayr	73	;-----------------------------------------------------------------;
		74	; ;
		75	; TCP_process_input: Process segments from the incoming TCP queue.;
		76	; ;
		77	; IN: / ;
		78	; OUT: / ;
		79	; ;
		80	;-----------------------------------------------------------------;
3545	hidnplayr	81	align 4
6011	hidnplayr	82	proc tcp_process_input
3545	hidnplayr	83
4339	hidnplayr	84	locals
		85	dataoffset dd ?
4344	hidnplayr	86	timestamp dd ?
4347	hidnplayr	87	temp_bits db ?
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
6908	ashmew2	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
6908	ashmew2	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
6908	ashmew2	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
6908	ashmew2	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
6908	ashmew2	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
6908	ashmew2	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
6908	ashmew2	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
6908	ashmew2	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
6908	ashmew2	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
6908	ashmew2	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
6908	ashmew2	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
6908	ashmew2	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
6908	ashmew2	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
6908	ashmew2	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:
6908	ashmew2	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]
6908	ashmew2	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]
6908	ashmew2	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	@@:
6908	ashmew2	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
6908	ashmew2	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
6908	ashmew2	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
6908	ashmew2	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
6908	ashmew2	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
6908	ashmew2	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
6908	ashmew2	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
6908	ashmew2	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:
6908	ashmew2	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:
6908	ashmew2	854	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Connection reset\n"
3545	hidnplayr	855	mov [ebx + SOCKET.errorcode], ECONNRESET
		856	.close:
6908	ashmew2	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
6710	clevermous	862	jmp .drop
3545	hidnplayr	863
6476	hidnplayr	864	;-----------------------------------------------------------------------------------
3545	hidnplayr	865	.rst_close:
6908	ashmew2	866	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Closing with reset\n"
6710	clevermous	867	jmp .unlock_and_close
3545	hidnplayr	868
6476	hidnplayr	869	;-----------------------------------------------------------------------------------
3545	hidnplayr	870	.no_rst:
		871
6476	hidnplayr	872	;-----------------------------------------------------------------------------------
		873	;
		874	; Handle SYN-full and ACK-less segments
		875	;
		876	;-----------------------------------------------------------------------------------
3545	hidnplayr	877
6476	hidnplayr	878	; If a SYN is in the window, then this is an error so we send an RST and drop the connection
		879
3545	hidnplayr	880	test [edx + TCP_header.Flags], TH_SYN
		881	jz .not_syn_full
		882
		883	mov eax, ebx
		884	mov ebx, ECONNRESET
6011	hidnplayr	885	call tcp_drop
3545	hidnplayr	886	jmp .drop_with_reset
		887	.not_syn_full:
		888
6476	hidnplayr	889	; If ACK bit is off, we drop the segment and return
3545	hidnplayr	890
		891	test [edx + TCP_header.Flags], TH_ACK
		892	jz .drop
		893
6476	hidnplayr	894	;----------------------------------------------------------------------------------
		895	;
		896	; ACK processing for SYN_RECEIVED state
		897	;
		898	;----------------------------------------------------------------------------------
		899
3545	hidnplayr	900	cmp [ebx + TCP_SOCKET.t_state], TCPS_SYN_RECEIVED
		901	jb .ack_processed ; states: closed, listen, syn_sent
		902	ja .no_syn_rcv ; established, fin_wait_1, fin_wait_2, close_wait, closing, last_ack, time_wait
		903
6908	ashmew2	904	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: state=syn_received\n"
3545	hidnplayr	905
		906	mov eax, [edx + TCP_header.AckNumber]
		907	cmp [ebx + TCP_SOCKET.SND_UNA], eax
		908	ja .drop_with_reset
		909	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		910	ja .drop_with_reset
		911
6476	hidnplayr	912	inc [TCPS_connects]
3545	hidnplayr	913
		914	mov eax, ebx
6011	hidnplayr	915	call socket_is_connected
3545	hidnplayr	916	mov [ebx + TCP_SOCKET.t_state], TCPS_ESTABLISHED
		917
		918	; Do window scaling?
		919
		920	test [ebx + TCP_SOCKET.t_flags], TF_RCVD_SCALE
		921	jz @f
		922	test [ebx + TCP_SOCKET.t_flags], TF_REQ_SCALE
		923	jz @f
		924
6476	hidnplayr	925	push word[ebx + TCP_SOCKET.requested_s_scale] ; Set send and receive scale factors to the received values
		926	pop word[ebx + TCP_SOCKET.SND_SCALE]
3545	hidnplayr	927	@@:
		928
6011	hidnplayr	929	call tcp_reassemble
3545	hidnplayr	930
		931	mov eax, [edx + TCP_header.SequenceNumber]
		932	dec eax
		933	mov [ebx + TCP_SOCKET.SND_WL1], eax
		934	.no_syn_rcv:
		935
6476	hidnplayr	936	;-----------------------------------------------------------------------------------
		937	;
		938	; ACK processing for SYN_RECEIVED state and higher
		939	;
		940	;-----------------------------------------------------------------------------------
		941
3545	hidnplayr	942	;-------------------------
6476	hidnplayr	943	; Check for duplicate ACKs
3545	hidnplayr	944
		945	mov eax, [edx + TCP_header.AckNumber]
		946	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
6476	hidnplayr	947	ja .dup_ack_complete
3545	hidnplayr	948
		949	test ecx, ecx
		950	jnz .reset_dupacks
		951
6476	hidnplayr	952	mov eax, dword[edx + TCP_header.Window]
3545	hidnplayr	953	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		954	jne .reset_dupacks
		955
6476	hidnplayr	956	inc [TCPS_rcvdupack]
6908	ashmew2	957	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Processing duplicate ACK\n"
3545	hidnplayr	958
		959	; If we have outstanding data, other than a window probe, this is a completely duplicate ACK
		960	; (window info didnt change) The ACK is the biggest we've seen and we've seen exactly our rexmt threshold of them,
		961	; assume a packet has been dropped and retransmit it. Kludge snd_nxt & the congestion window so we send only this one packet.
		962
3600	hidnplayr	963	test [ebx + TCP_SOCKET.timer_flags], timer_flag_retransmission
6476	hidnplayr	964	jz .reset_dupacks
3545	hidnplayr	965
		966	mov eax, [edx + TCP_header.AckNumber]
		967	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
6476	hidnplayr	968	jne .reset_dupacks
3545	hidnplayr	969
6476	hidnplayr	970	; Increment dupplicat ACK counter
		971	; If it reaches the threshold, re-transmit the missing segment
3545	hidnplayr	972
		973	inc [ebx + TCP_SOCKET.t_dupacks]
		974	cmp [ebx + TCP_SOCKET.t_dupacks], TCP_re_xmit_thresh
6476	hidnplayr	975	jb .dup_ack_complete
		976	ja .another_lost
3545	hidnplayr	977
6908	ashmew2	978	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Re-transmitting lost segment\n"
6476	hidnplayr	979
3545	hidnplayr	980	push [ebx + TCP_SOCKET.SND_NXT] ; >>>>
		981
		982	mov eax, [ebx + TCP_SOCKET.SND_WND]
		983	cmp eax, [ebx + TCP_SOCKET.SND_CWND]
4296	hidnplayr	984	jbe @f
		985	mov eax, [ebx + TCP_SOCKET.SND_CWND]
		986	@@:
3545	hidnplayr	987	shr eax, 1
		988	push edx
		989	xor edx, edx
		990	div [ebx + TCP_SOCKET.t_maxseg]
		991	cmp eax, 2
		992	ja @f
		993	xor eax, eax
		994	mov al, 2
		995	@@:
		996	mul [ebx + TCP_SOCKET.t_maxseg]
		997	pop edx
		998	mov [ebx + TCP_SOCKET.SND_SSTHRESH], eax
		999
3600	hidnplayr	1000	and [ebx + TCP_SOCKET.timer_flags], not timer_flag_retransmission ; turn off retransmission timer
3545	hidnplayr	1001	mov [ebx + TCP_SOCKET.t_rtt], 0
		1002	mov eax, [edx + TCP_header.AckNumber]
		1003	mov [ebx + TCP_SOCKET.SND_NXT], eax
		1004	mov eax, [ebx + TCP_SOCKET.t_maxseg]
		1005	mov [ebx + TCP_SOCKET.SND_CWND], eax
		1006
		1007	; Unlock the socket
6476	hidnplayr	1008
3545	hidnplayr	1009	push ebx
		1010	lea ecx, [ebx + SOCKET.mutex]
		1011	call mutex_unlock
		1012
		1013	; retransmit missing segment
6476	hidnplayr	1014
3545	hidnplayr	1015	mov eax, [esp]
6011	hidnplayr	1016	call tcp_output
3545	hidnplayr	1017
		1018	; Lock the socket again
6476	hidnplayr	1019
3545	hidnplayr	1020	mov ecx, [esp]
		1021	add ecx, SOCKET.mutex
		1022	call mutex_lock
3711	clevermous	1023	pop ebx
3545	hidnplayr	1024
		1025	; Continue processing
6476	hidnplayr	1026
3545	hidnplayr	1027	xor edx, edx
		1028	mov eax, [ebx + TCP_SOCKET.t_maxseg]
		1029	mul [ebx + TCP_SOCKET.t_dupacks]
		1030	add eax, [ebx + TCP_SOCKET.SND_SSTHRESH]
		1031	mov [ebx + TCP_SOCKET.SND_CWND], eax
		1032
		1033	pop eax ; <<<<
		1034	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		1035	jb @f
		1036	mov [ebx + TCP_SOCKET.SND_NXT], eax
		1037	@@:
		1038	jmp .drop
		1039
6476	hidnplayr	1040	.another_lost:
6908	ashmew2	1041	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Increasing congestion window\n"
3545	hidnplayr	1042
		1043	mov eax, [ebx + TCP_SOCKET.t_maxseg]
		1044	add [ebx + TCP_SOCKET.SND_CWND], eax
		1045
		1046	; Unlock the socket
6476	hidnplayr	1047
3545	hidnplayr	1048	push ebx
		1049	lea ecx, [ebx + SOCKET.mutex]
		1050	call mutex_unlock
		1051
6476	hidnplayr	1052	; retransmit missing segment, again
		1053
3545	hidnplayr	1054	mov eax, [esp]
6011	hidnplayr	1055	call tcp_output
3545	hidnplayr	1056
		1057	; Lock the socket again
6476	hidnplayr	1058
3545	hidnplayr	1059	mov ecx, [esp]
		1060	add ecx, SOCKET.mutex
		1061	call mutex_lock
		1062	pop ebx
		1063
6476	hidnplayr	1064	; And drop the incoming segment
		1065
3545	hidnplayr	1066	jmp .drop
		1067
6476	hidnplayr	1068	.reset_dupacks: ; We got a new ACK, reset duplicate ACK counter
		1069	mov [ebx + TCP_SOCKET.t_dupacks], 0
		1070	jmp .ack_processed
3545	hidnplayr	1071
6476	hidnplayr	1072	.dup_ack_complete:
3545	hidnplayr	1073
		1074	;-------------------------------------------------
		1075	; If the congestion window was inflated to account
		1076	; for the other side's cached packets, retract it
		1077
		1078	mov eax, [ebx + TCP_SOCKET.SND_SSTHRESH]
		1079	cmp eax, [ebx + TCP_SOCKET.SND_CWND]
		1080	ja @f
		1081	cmp [ebx + TCP_SOCKET.t_dupacks], TCP_re_xmit_thresh
		1082	jbe @f
		1083	mov [ebx + TCP_SOCKET.SND_CWND], eax
		1084	@@:
		1085
		1086	mov [ebx + TCP_SOCKET.t_dupacks], 0
		1087
		1088	mov eax, [edx + TCP_header.AckNumber]
		1089	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		1090	jbe @f
5442	hidnplayr	1091	inc [TCPS_rcvacktoomuch]
3545	hidnplayr	1092	jmp .drop_after_ack
		1093	@@:
		1094
		1095	mov edi, [edx + TCP_header.AckNumber]
		1096	sub edi, [ebx + TCP_SOCKET.SND_UNA] ; now we got the number of acked bytes in edi
5442	hidnplayr	1097	inc [TCPS_rcvackpack]
		1098	add [TCPS_rcvackbyte], edi
6908	ashmew2	1099	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: acceptable ACK for %u bytes\n", edi
3545	hidnplayr	1100
6476	hidnplayr	1101	;-----------------------------------------------------------------------------------
		1102	;
4347	hidnplayr	1103	; RTT measurements and retransmission timer
6476	hidnplayr	1104	;
		1105	;-----------------------------------------------------------------------------------
3545	hidnplayr	1106
		1107	; If we have a timestamp, update smoothed RTT
		1108
4347	hidnplayr	1109	test [temp_bits], TCP_BIT_TIMESTAMP
3545	hidnplayr	1110	jz .timestamp_not_present
4344	hidnplayr	1111	mov eax, [timestamp]
3545	hidnplayr	1112	sub eax, [ebx + TCP_SOCKET.ts_ecr]
		1113	inc eax
6011	hidnplayr	1114	call tcp_xmit_timer
3545	hidnplayr	1115	jmp .rtt_done_
		1116
		1117	; If no timestamp but transmit timer is running and timed sequence number was acked,
		1118	; update smoothed RTT. Since we now have an RTT measurement, cancel the timer backoff
		1119	; (Phil Karn's retransmit algo)
		1120	; Recompute the initial retransmit timer
		1121
		1122	.timestamp_not_present:
		1123	mov eax, [edx + TCP_header.AckNumber]
		1124	cmp eax, [ebx + TCP_SOCKET.t_rtseq]
		1125	jbe .rtt_done_
		1126	mov eax, [ebx + TCP_SOCKET.t_rtt]
		1127	test eax, eax
		1128	jz .rtt_done_
6011	hidnplayr	1129	call tcp_xmit_timer
3545	hidnplayr	1130	.rtt_done_:
		1131
		1132	; If all outstanding data is acked, stop retransmit timer and remember to restart (more output or persist)
		1133	; If there is more data to be acked, restart retransmit timer, using current (possible backed-off) value.
		1134
		1135	mov eax, [ebx + TCP_SOCKET.SND_MAX]
		1136	cmp eax, [edx + TCP_header.AckNumber]
		1137	jne .more_data
3600	hidnplayr	1138	and [ebx + TCP_SOCKET.timer_flags], not timer_flag_retransmission
4347	hidnplayr	1139	or [temp_bits], TCP_BIT_NEEDOUTPUT
3545	hidnplayr	1140	jmp .no_restart
		1141	.more_data:
3600	hidnplayr	1142	test [ebx + TCP_SOCKET.timer_flags], timer_flag_persist
		1143	jnz .no_restart
3545	hidnplayr	1144
		1145	mov eax, [ebx + TCP_SOCKET.t_rxtcur]
		1146	mov [ebx + TCP_SOCKET.timer_retransmission], eax
3600	hidnplayr	1147	or [ebx + TCP_SOCKET.timer_flags], timer_flag_retransmission
3545	hidnplayr	1148	.no_restart:
		1149
6476	hidnplayr	1150	;-----------------------------------------------------------------------------------
		1151	;
3545	hidnplayr	1152	; Open congestion window in response to ACKs
6476	hidnplayr	1153	;
		1154	;-----------------------------------------------------------------------------------
3545	hidnplayr	1155
6476	hidnplayr	1156	; If the window gives us less then sstresh packets in flight, open exponentially.
		1157	; Otherwise, open lineary
		1158
3545	hidnplayr	1159	mov esi, [ebx + TCP_SOCKET.SND_CWND]
		1160	mov eax, [ebx + TCP_SOCKET.t_maxseg]
		1161	cmp esi, [ebx + TCP_SOCKET.SND_SSTHRESH]
		1162	jbe @f
		1163	push edx
		1164	push eax
6476	hidnplayr	1165	mul eax ; t_maxseg*t_maxseg
		1166	div esi ; t_maxseg*t_maxseg/snd_cwnd
		1167	pop edx ; t_maxseg
		1168	shr edx, 3 ; t_maxseg/8
		1169	add eax, edx ; t_maxseg*t_maxseg/snd_cwnd + t_maxseg/8
3545	hidnplayr	1170	pop edx
		1171	@@:
		1172	add esi, eax
		1173
		1174	push ecx
		1175	mov cl, [ebx + TCP_SOCKET.SND_SCALE]
		1176	mov eax, TCP_max_win
		1177	shl eax, cl
		1178	pop ecx
		1179
		1180	cmp esi, eax
4296	hidnplayr	1181	jbe @f
		1182	mov esi, eax
		1183	@@:
3545	hidnplayr	1184	mov [ebx + TCP_SOCKET.SND_CWND], esi
		1185
6476	hidnplayr	1186	;-----------------------------------------------------------------------------------
		1187	;
3545	hidnplayr	1188	; Remove acknowledged data from send buffer
6476	hidnplayr	1189	;
		1190	;-----------------------------------------------------------------------------------
3545	hidnplayr	1191
6476	hidnplayr	1192	; If the number of bytes acknowledged exceeds the number of bytes on the send buffer,
		1193	; snd_wnd is decremented by the number of bytes in the send buffer and TCP knows
		1194	; that its FIN has been ACKed. (FIN occupies 1 byte in the sequence number space)
		1195
3545	hidnplayr	1196	cmp edi, [ebx + STREAM_SOCKET.snd.size]
6476	hidnplayr	1197	jbe .no_fin_ack
3545	hidnplayr	1198
6476	hidnplayr	1199	; Drop all data in output buffer
		1200
3545	hidnplayr	1201	push ecx edx ebx
		1202	mov ecx, [ebx + STREAM_SOCKET.snd.size]
6476	hidnplayr	1203	sub [ebx + TCP_SOCKET.SND_WND], ecx
3545	hidnplayr	1204	lea eax, [ebx + STREAM_SOCKET.snd]
6011	hidnplayr	1205	call socket_ring_free
3545	hidnplayr	1206	pop ebx edx ecx
		1207
6908	ashmew2	1208	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: our FIN is acked\n"
5133	hidnplayr	1209	or [temp_bits], TCP_BIT_FIN_IS_ACKED
6476	hidnplayr	1210	jmp .ack_complete
		1211	.no_fin_ack:
3545	hidnplayr	1212
6476	hidnplayr	1213	; Drop acknowledged data
3545	hidnplayr	1214
		1215	push ecx edx ebx
		1216	mov ecx, edi
		1217	lea eax, [ebx + STREAM_SOCKET.snd]
6011	hidnplayr	1218	call socket_ring_free
3545	hidnplayr	1219	pop ebx
		1220	sub [ebx + TCP_SOCKET.SND_WND], ecx
		1221	pop edx ecx
6476	hidnplayr	1222	.ack_complete:
3545	hidnplayr	1223
6476	hidnplayr	1224	;-----------------------------------------------------------------------------------
		1225	;
3545	hidnplayr	1226	; Wake up process waiting on send buffer
6476	hidnplayr	1227	;
		1228	;-----------------------------------------------------------------------------------
3545	hidnplayr	1229
		1230	mov eax, ebx
6011	hidnplayr	1231	call socket_notify
3545	hidnplayr	1232
		1233	; Update TCPS
6476	hidnplayr	1234
3545	hidnplayr	1235	mov eax, [edx + TCP_header.AckNumber]
		1236	mov [ebx + TCP_SOCKET.SND_UNA], eax
		1237	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		1238	jb @f
		1239	mov [ebx + TCP_SOCKET.SND_NXT], eax
		1240	@@:
		1241
6476	hidnplayr	1242	;-----------------------------------------------------------------------------------
		1243	;
		1244	; State specific ACK handeling
		1245	;
		1246	;-----------------------------------------------------------------------------------
3545	hidnplayr	1247
		1248	mov eax, [ebx + TCP_SOCKET.t_state]
6476	hidnplayr	1249	jmp dword[.ack_sw_list+eax*4]
3545	hidnplayr	1250
6476	hidnplayr	1251	.ack_sw_list:
3545	hidnplayr	1252	dd .ack_processed ; TCPS_CLOSED
		1253	dd .ack_processed ; TCPS_LISTEN
		1254	dd .ack_processed ; TCPS_SYN_SENT
		1255	dd .ack_processed ; TCPS_SYN_RECEIVED
		1256	dd .ack_processed ; TCPS_ESTABLISHED
		1257	dd .ack_processed ; TCPS_CLOSE_WAIT
		1258	dd .ack_fw1 ; TCPS_FIN_WAIT_1
		1259	dd .ack_c ; TCPS_CLOSING
		1260	dd .ack_la ; TCPS_LAST_ACK
		1261	dd .ack_processed ; TCPS_FIN_WAIT_2
		1262	dd .ack_tw ; TCPS_TIMED_WAIT
		1263
6476	hidnplayr	1264	;-----------------------------------------------------------------------------------
		1265	.ack_fw1:
		1266	; If our FIN is now acked, enter FIN_WAIT_2
3545	hidnplayr	1267
5133	hidnplayr	1268	test [temp_bits], TCP_BIT_FIN_IS_ACKED
		1269	jz .ack_processed
3545	hidnplayr	1270
6476	hidnplayr	1271	; If we can't receive any more data, then closing user can proceed.
		1272	; Starting the timer is contrary to the specification, but if we dont get a FIN,
		1273	; we'll hang forever.
		1274
3545	hidnplayr	1275	test [ebx + SOCKET.state], SS_CANTRCVMORE
		1276	jnz @f
		1277	mov eax, ebx
6011	hidnplayr	1278	call socket_is_disconnected
3545	hidnplayr	1279	mov [ebx + TCP_SOCKET.timer_timed_wait], TCP_time_max_idle
3600	hidnplayr	1280	or [ebx + TCP_SOCKET.timer_flags], timer_flag_wait
3545	hidnplayr	1281	@@:
		1282	mov [ebx + TCP_SOCKET.t_state], TCPS_FIN_WAIT_2
		1283	jmp .ack_processed
		1284
6476	hidnplayr	1285	;-----------------------------------------------------------------------------------
3545	hidnplayr	1286	.ack_c:
6476	hidnplayr	1287	; Enter the TIME_WAIT state if our FIN is acked in CLOSED state.
		1288
5133	hidnplayr	1289	test [temp_bits], TCP_BIT_FIN_IS_ACKED
		1290	jz .ack_processed
3545	hidnplayr	1291
6476	hidnplayr	1292	mov [ebx + TCP_SOCKET.t_state], TCPS_TIME_WAIT
3545	hidnplayr	1293	mov eax, ebx
6011	hidnplayr	1294	call tcp_cancel_timers
3545	hidnplayr	1295	mov [ebx + TCP_SOCKET.timer_timed_wait], 2 * TCP_time_MSL
3600	hidnplayr	1296	or [ebx + TCP_SOCKET.timer_flags], timer_flag_wait
3545	hidnplayr	1297	mov eax, ebx
6011	hidnplayr	1298	call socket_is_disconnected
3545	hidnplayr	1299	jmp .ack_processed
		1300
6476	hidnplayr	1301	;-----------------------------------------------------------------------------------
3545	hidnplayr	1302	.ack_la:
6476	hidnplayr	1303	; In LAST_ACK state, we may still be waiting for data to drain and/or to be acked.
		1304	; If our FIN is acked however, enter CLOSED state and return.
		1305
5133	hidnplayr	1306	test [temp_bits], TCP_BIT_FIN_IS_ACKED
		1307	jz .ack_processed
3545	hidnplayr	1308
6710	clevermous	1309	.unlock_and_close:
3652	hidnplayr	1310	push ebx
		1311	lea ecx, [ebx + SOCKET.mutex]
		1312	call mutex_unlock
6476	hidnplayr	1313	pop eax
3652	hidnplayr	1314
6011	hidnplayr	1315	call tcp_close
4366	hidnplayr	1316	jmp .drop_no_socket
3545	hidnplayr	1317
6476	hidnplayr	1318	;-----------------------------------------------------------------------------------
3545	hidnplayr	1319	.ack_tw:
6476	hidnplayr	1320	; In TIME_WAIT state the only thing that should arrive is a retransmission of the remote FIN.
		1321	; Acknowledge it and restart the FINACK timer
		1322
		1323	mov [ebx + TCP_SOCKET.timer_timed_wait], 2*TCP_time_MSL
		1324	or [ebx + TCP_SOCKET.timer_flags], timer_flag_2msl
3545	hidnplayr	1325	jmp .drop_after_ack
		1326
6476	hidnplayr	1327	;-----------------------------------------------------------------------------------
		1328	;
		1329	; Initiation of Passive Open?
		1330	;
		1331	;-----------------------------------------------------------------------------------
3545	hidnplayr	1332
6476	hidnplayr	1333	.state_listen:
6908	ashmew2	1334	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: state=listen\n"
3545	hidnplayr	1335
		1336	test [edx + TCP_header.Flags], TH_RST
		1337	jnz .drop
		1338
		1339	test [edx + TCP_header.Flags], TH_ACK
		1340	jnz .drop_with_reset
		1341
		1342	test [edx + TCP_header.Flags], TH_SYN
		1343	jz .drop
		1344
6476	hidnplayr	1345	inc [TCPS_accepts]
5442	hidnplayr	1346
3545	hidnplayr	1347	;;; TODO: check if it's a broadcast or multicast, and drop if so
		1348
6476	hidnplayr	1349	;-------------------------------------------
		1350	; Processing of SYN received in LISTEN state
		1351
5842	hidnplayr	1352	push [edi + IPv4_header.SourceAddress]
3545	hidnplayr	1353	pop [ebx + IP_SOCKET.RemoteIP]
		1354
		1355	push [edx + TCP_header.SourcePort]
		1356	pop [ebx + TCP_SOCKET.RemotePort]
		1357
		1358	push [edx + TCP_header.SequenceNumber]
		1359	pop [ebx + TCP_SOCKET.IRS]
		1360
		1361	mov eax, [TCP_sequence_num]
6476	hidnplayr	1362	add [TCP_sequence_num], TCP_ISSINCR / 2
3545	hidnplayr	1363	mov [ebx + TCP_SOCKET.ISS], eax
		1364	mov [ebx + TCP_SOCKET.SND_NXT], eax
		1365
6011	hidnplayr	1366	tcp_sendseqinit ebx
		1367	tcp_rcvseqinit ebx
3545	hidnplayr	1368
		1369	mov [ebx + TCP_SOCKET.t_state], TCPS_SYN_RECEIVED
4347	hidnplayr	1370	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
3545	hidnplayr	1371	mov [ebx + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval ;;;; macro
3600	hidnplayr	1372	or [ebx + TCP_SOCKET.timer_flags], timer_flag_keepalive
3545	hidnplayr	1373
		1374	lea eax, [ebx + STREAM_SOCKET.snd]
6011	hidnplayr	1375	call socket_ring_create
5155	hidnplayr	1376	test eax, eax
		1377	jz .drop
3545	hidnplayr	1378
		1379	lea eax, [ebx + STREAM_SOCKET.rcv]
6011	hidnplayr	1380	call socket_ring_create
5155	hidnplayr	1381	test eax, eax
		1382	jz .drop
3545	hidnplayr	1383
4347	hidnplayr	1384	and [temp_bits], not TCP_BIT_DROPSOCKET
3545	hidnplayr	1385
3674	hidnplayr	1386	pusha
		1387	mov eax, ebx
6011	hidnplayr	1388	call socket_notify
3674	hidnplayr	1389	popa
3545	hidnplayr	1390
5133	hidnplayr	1391	jmp .trim
3545	hidnplayr	1392
6476	hidnplayr	1393	;-----------------------------------------------------------------------------------
		1394	;
		1395	; Completion of active open?
		1396	;
		1397	;-----------------------------------------------------------------------------------
3545	hidnplayr	1398
6476	hidnplayr	1399	.state_syn_sent:
6908	ashmew2	1400	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: state=syn_sent\n"
3545	hidnplayr	1401
		1402	test [edx + TCP_header.Flags], TH_ACK
		1403	jz @f
		1404
		1405	mov eax, [edx + TCP_header.AckNumber]
		1406	cmp eax, [ebx + TCP_SOCKET.ISS]
		1407	jbe .drop_with_reset
		1408
		1409	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		1410	ja .drop_with_reset
		1411	@@:
		1412
		1413	test [edx + TCP_header.Flags], TH_RST
		1414	jz @f
		1415
		1416	test [edx + TCP_header.Flags], TH_ACK
		1417	jz .drop
		1418
		1419	mov eax, ebx
		1420	mov ebx, ECONNREFUSED
6011	hidnplayr	1421	call tcp_drop
3545	hidnplayr	1422	jmp .drop
		1423	@@:
		1424
6476	hidnplayr	1425	;-----------------------------------------------------------------------------------
		1426	;
		1427	; Process received SYN in response to an active open
		1428	;
		1429	;-----------------------------------------------------------------------------------
		1430
3545	hidnplayr	1431	test [edx + TCP_header.Flags], TH_SYN
		1432	jz .drop
		1433
		1434	test [edx + TCP_header.Flags], TH_ACK
6476	hidnplayr	1435	jz @f
3545	hidnplayr	1436
		1437	mov eax, [edx + TCP_header.AckNumber]
		1438	mov [ebx + TCP_SOCKET.SND_UNA], eax
		1439	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		1440	jbe @f
		1441	mov [ebx + TCP_SOCKET.SND_NXT], eax
		1442
3600	hidnplayr	1443	and [ebx + TCP_SOCKET.timer_flags], not timer_flag_retransmission ; disable retransmission timer
6476	hidnplayr	1444	@@:
3545	hidnplayr	1445
		1446	push [edx + TCP_header.SequenceNumber]
		1447	pop [ebx + TCP_SOCKET.IRS]
		1448
6011	hidnplayr	1449	tcp_rcvseqinit ebx
3545	hidnplayr	1450
		1451	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
		1452
		1453	mov eax, [ebx + TCP_SOCKET.SND_UNA]
		1454	cmp eax, [ebx + TCP_SOCKET.ISS]
		1455	jbe .simultaneous_open
		1456
		1457	test [edx + TCP_header.Flags], TH_ACK
		1458	jz .simultaneous_open
		1459
6908	ashmew2	1460	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: active open\n"
3545	hidnplayr	1461
6476	hidnplayr	1462	inc [TCPS_connects]
3545	hidnplayr	1463
		1464	; set socket state to connected
6476	hidnplayr	1465
3674	hidnplayr	1466	push eax
		1467	mov eax, ebx
6011	hidnplayr	1468	call socket_is_connected
3674	hidnplayr	1469	pop eax
3545	hidnplayr	1470	mov [ebx + TCP_SOCKET.t_state], TCPS_ESTABLISHED
		1471
		1472	; Do window scaling on this connection ?
6476	hidnplayr	1473
3545	hidnplayr	1474	mov eax, [ebx + TCP_SOCKET.t_flags]
		1475	and eax, TF_REQ_SCALE or TF_RCVD_SCALE
		1476	cmp eax, TF_REQ_SCALE or TF_RCVD_SCALE
		1477	jne .no_scaling
		1478
6011	hidnplayr	1479	mov ax, word[ebx + TCP_SOCKET.requested_s_scale]
		1480	mov word[ebx + TCP_SOCKET.SND_SCALE], ax
3545	hidnplayr	1481	.no_scaling:
		1482
		1483	;;; TODO: reassemble packets queue
		1484
6476	hidnplayr	1485	; If we didnt have time to re-transmit the SYN,
		1486	; Use its rtt as our initial srtt & rtt var.
		1487
3545	hidnplayr	1488	mov eax, [ebx + TCP_SOCKET.t_rtt]
		1489	test eax, eax
5133	hidnplayr	1490	je .trim
6011	hidnplayr	1491	call tcp_xmit_timer
5133	hidnplayr	1492	jmp .trim
3545	hidnplayr	1493
6476	hidnplayr	1494	;-----------------------------------------------------------------------------------
		1495	;
		1496	; Simultaneous open (We have received a SYN but no ACK)
		1497	;
		1498	;-----------------------------------------------------------------------------------
		1499
3545	hidnplayr	1500	.simultaneous_open:
6908	ashmew2	1501	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: simultaneous open\n"
3545	hidnplayr	1502	mov [ebx + TCP_SOCKET.t_state], TCPS_SYN_RECEIVED
		1503
6476	hidnplayr	1504	;-----------------------------------------------------------------------------------
		1505	;
3545	hidnplayr	1506	; Common processing for receipt of SYN
6476	hidnplayr	1507	;
		1508	;-----------------------------------------------------------------------------------
3545	hidnplayr	1509
5133	hidnplayr	1510	.trim:
6476	hidnplayr	1511	; Advance sequence number to correspond to first data byte.
		1512	; If data, trim to stay within window, dropping FIN if necessary
		1513
3545	hidnplayr	1514	inc [edx + TCP_header.SequenceNumber]
		1515
4339	hidnplayr	1516	; Drop any received data that doesnt fit in the receive window.
6476	hidnplayr	1517
4339	hidnplayr	1518	cmp ecx, [ebx + TCP_SOCKET.RCV_WND]
		1519	jbe .dont_trim
3545	hidnplayr	1520
6908	ashmew2	1521	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: received data does not fit in window, trimming %u bytes\n", eax
6476	hidnplayr	1522	inc [TCPS_rcvpackafterwin]
		1523	sub ecx, [ebx + TCP_SOCKET.RCV_WND]
		1524	add [TCPS_rcvbyteafterwin], ecx
		1525
		1526	and [edx + TCP_header.Flags], not (TH_FIN)
4339	hidnplayr	1527	mov ecx, [ebx + TCP_SOCKET.RCV_WND]
		1528
		1529	.dont_trim:
3545	hidnplayr	1530	mov eax, [edx + TCP_header.SequenceNumber]
		1531	mov [ebx + TCP_SOCKET.RCV_UP], eax
		1532	dec eax
		1533	mov [ebx + TCP_SOCKET.SND_WL1], eax
		1534
6476	hidnplayr	1535	;-----------------------------------------------------------------------------------
		1536	;
		1537	; Update window information (step 6 in RFC793)
		1538	;
		1539	;-----------------------------------------------------------------------------------
		1540
3545	hidnplayr	1541	.ack_processed:
6908	ashmew2	1542	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: ACK processed\n"
3545	hidnplayr	1543
6476	hidnplayr	1544	; dont look at window if no ACK
3545	hidnplayr	1545
		1546	test [edx + TCP_header.Flags], TH_ACK
		1547	jz .no_window_update
		1548
6476	hidnplayr	1549	; Does the segment contain new data?
		1550
3545	hidnplayr	1551	mov eax, [ebx + TCP_SOCKET.SND_WL1]
		1552	cmp eax, [edx + TCP_header.SequenceNumber]
		1553	jb .update_window
		1554	ja @f
		1555
6476	hidnplayr	1556	; No new data but a new ACK ?
		1557
3545	hidnplayr	1558	mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1559	cmp eax, [edx + TCP_header.AckNumber]
		1560	jb .update_window
		1561	@@:
		1562
6476	hidnplayr	1563	; No new data or ACK but advertised window is larger then current window?
		1564
		1565	mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1566	cmp eax, [edx + TCP_header.AckNumber]
		1567	jne .no_window_update
		1568
		1569	mov eax, dword[edx + TCP_header.Window]
3545	hidnplayr	1570	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		1571	jbe .no_window_update
		1572
6476	hidnplayr	1573
		1574	; Keep track of pure window updates
3545	hidnplayr	1575	.update_window:
6476	hidnplayr	1576	test ecx, ecx
		1577	jnz @f
		1578	mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1579	cmp eax, [edx + TCP_header.AckNumber]
		1580	jne @f
		1581	mov eax, dword[edx + TCP_header.Window]
		1582	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		1583	jbe @f
		1584	inc [TCPS_rcvwinupd]
		1585	@@:
3545	hidnplayr	1586
6476	hidnplayr	1587	mov eax, dword[edx + TCP_header.Window]
		1588	mov [ebx + TCP_SOCKET.SND_WND], eax
3545	hidnplayr	1589	cmp eax, [ebx + TCP_SOCKET.max_sndwnd]
		1590	jbe @f
		1591	mov [ebx + TCP_SOCKET.max_sndwnd], eax
		1592	@@:
		1593
6908	ashmew2	1594	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Updating window to %u\n", eax
3545	hidnplayr	1595
		1596	push [edx + TCP_header.SequenceNumber]
		1597	pop [ebx + TCP_SOCKET.SND_WL1]
		1598
		1599	push [edx + TCP_header.AckNumber]
		1600	pop [ebx + TCP_SOCKET.SND_WL2]
		1601
4347	hidnplayr	1602	or [temp_bits], TCP_BIT_NEEDOUTPUT
3545	hidnplayr	1603	.no_window_update:
		1604
6476	hidnplayr	1605	;-----------------------------------------------------------------------------------
		1606	;
		1607	; Process URG flag
		1608	;
		1609	;-----------------------------------------------------------------------------------
3545	hidnplayr	1610
		1611	test [edx + TCP_header.Flags], TH_URG
		1612	jz .not_urgent
		1613
		1614	cmp [edx + TCP_header.UrgentPointer], 0
		1615	jz .not_urgent
		1616
6476	hidnplayr	1617	cmp [ebx + TCP_SOCKET.t_state], TCPS_TIME_WAIT
3545	hidnplayr	1618	je .not_urgent
		1619
		1620	; Ignore bogus urgent offsets
		1621
		1622	movzx eax, [edx + TCP_header.UrgentPointer]
		1623	add eax, [ebx + STREAM_SOCKET.rcv.size]
6413	hidnplayr	1624	cmp eax, SOCKET_BUFFER_SIZE
3545	hidnplayr	1625	jbe .not_urgent
		1626
		1627	mov [edx + TCP_header.UrgentPointer], 0
		1628	and [edx + TCP_header.Flags], not (TH_URG)
		1629	jmp .do_data
		1630
		1631	.not_urgent:
		1632
		1633	; processing of received urgent pointer
		1634
		1635	;;; TODO (1051-1093)
		1636
6476	hidnplayr	1637	;-----------------------------------------------------------------------------------
		1638	;
		1639	; Process the data
		1640	;
		1641	;-----------------------------------------------------------------------------------
3545	hidnplayr	1642
		1643	.do_data:
6476	hidnplayr	1644	cmp [ebx + TCP_SOCKET.t_state], TCPS_TIME_WAIT
3545	hidnplayr	1645	jae .final_processing
		1646
		1647	test [edx + TCP_header.Flags], TH_FIN
		1648	jnz @f
		1649
		1650	test ecx, ecx
3756	hidnplayr	1651	jz .final_processing
3545	hidnplayr	1652	@@:
		1653
		1654	; The segment is in order?
6476	hidnplayr	1655
3545	hidnplayr	1656	mov eax, [edx + TCP_header.SequenceNumber]
		1657	cmp eax, [ebx + TCP_SOCKET.RCV_NXT]
		1658	jne .out_of_order
		1659
		1660	; The reassembly queue is empty?
6476	hidnplayr	1661
3545	hidnplayr	1662	cmp [ebx + TCP_SOCKET.seg_next], 0
		1663	jne .out_of_order
		1664
		1665	; The connection is established?
6476	hidnplayr	1666
3545	hidnplayr	1667	cmp [ebx + TCP_SOCKET.t_state], TCPS_ESTABLISHED
		1668	jne .out_of_order
		1669
		1670	; Ok, lets do this.. Set delayed ACK flag and copy data into socket buffer
6476	hidnplayr	1671
3545	hidnplayr	1672	or [ebx + TCP_SOCKET.t_flags], TF_DELACK
		1673
		1674	pusha
4339	hidnplayr	1675	mov esi, [dataoffset]
3545	hidnplayr	1676	add esi, edx
		1677	lea eax, [ebx + STREAM_SOCKET.rcv]
6011	hidnplayr	1678	call socket_ring_write ; Add the data to the socket buffer
3545	hidnplayr	1679	add [ebx + TCP_SOCKET.RCV_NXT], ecx ; Update sequence number with number of bytes we have copied
		1680	popa
		1681
		1682	; Wake up the sleeping process
6476	hidnplayr	1683
3545	hidnplayr	1684	mov eax, ebx
6011	hidnplayr	1685	call socket_notify
3545	hidnplayr	1686
		1687	jmp .data_done
		1688
		1689	.out_of_order:
6908	ashmew2	1690	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP data is out of order!\nSequencenumber is %u, we expected %u.\n", \
4339	hidnplayr	1691	[edx + TCP_header.SequenceNumber], [ebx + TCP_SOCKET.RCV_NXT]
3545	hidnplayr	1692
		1693	; Uh-oh, some data is out of order, lets call TCP reassemble for help
		1694
6011	hidnplayr	1695	call tcp_reassemble
3545	hidnplayr	1696
4339	hidnplayr	1697	; Generate ACK immediately, to let the other end know that a segment was received out of order,
		1698	; and to tell it what sequence number is expected. This aids the fast-retransmit algorithm.
6476	hidnplayr	1699
3545	hidnplayr	1700	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
		1701	.data_done:
		1702
6476	hidnplayr	1703	;-----------------------------------------------------------------------------------
		1704	;
		1705	; Process FIN
		1706	;
		1707	;-----------------------------------------------------------------------------------
3545	hidnplayr	1708
		1709	test [edx + TCP_header.Flags], TH_FIN
		1710	jz .final_processing
		1711
6908	ashmew2	1712	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Processing FIN\n"
3545	hidnplayr	1713
6476	hidnplayr	1714	cmp [ebx + TCP_SOCKET.t_state], TCPS_TIME_WAIT
3545	hidnplayr	1715	jae .not_first_fin
		1716
6908	ashmew2	1717	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: First FIN for this connection\n"
3545	hidnplayr	1718
		1719	mov eax, ebx
6011	hidnplayr	1720	call socket_cant_recv_more
3545	hidnplayr	1721
4347	hidnplayr	1722	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
3545	hidnplayr	1723	inc [ebx + TCP_SOCKET.RCV_NXT]
		1724
		1725	.not_first_fin:
		1726	mov eax, [ebx + TCP_SOCKET.t_state]
6476	hidnplayr	1727	jmp dword[.fin_sw_list+eax*4]
3545	hidnplayr	1728
6476	hidnplayr	1729	.fin_sw_list:
3545	hidnplayr	1730	dd .final_processing ; TCPS_CLOSED
		1731	dd .final_processing ; TCPS_LISTEN
		1732	dd .final_processing ; TCPS_SYN_SENT
		1733	dd .fin_syn_est ; TCPS_SYN_RECEIVED
		1734	dd .fin_syn_est ; TCPS_ESTABLISHED
		1735	dd .final_processing ; TCPS_CLOSE_WAIT
		1736	dd .fin_wait1 ; TCPS_FIN_WAIT_1
		1737	dd .final_processing ; TCPS_CLOSING
		1738	dd .final_processing ; TCPS_LAST_ACK
		1739	dd .fin_wait2 ; TCPS_FIN_WAIT_2
		1740	dd .fin_timed ; TCPS_TIMED_WAIT
		1741
6476	hidnplayr	1742	;-----------------------------------------------------------------------------------
3545	hidnplayr	1743	.fin_syn_est:
6476	hidnplayr	1744	; In SYN_RECEIVED and ESTABLISHED state, enter the CLOSE_WAIT state
		1745
3545	hidnplayr	1746	mov [ebx + TCP_SOCKET.t_state], TCPS_CLOSE_WAIT
		1747	jmp .final_processing
		1748
6476	hidnplayr	1749	;-----------------------------------------------------------------------------------
3545	hidnplayr	1750	.fin_wait1:
6476	hidnplayr	1751	; From FIN_WAIT_1 state, enter CLOSING state (our FIN has not been ACKed)
		1752
3545	hidnplayr	1753	mov [ebx + TCP_SOCKET.t_state], TCPS_CLOSING
		1754	jmp .final_processing
		1755
6476	hidnplayr	1756	;-----------------------------------------------------------------------------------
3545	hidnplayr	1757	.fin_wait2:
6476	hidnplayr	1758	; From FIN_WAIT_2 state, enter TIME_WAIT state and start the timer
		1759
		1760	mov [ebx + TCP_SOCKET.t_state], TCPS_TIME_WAIT
3545	hidnplayr	1761	mov eax, ebx
6011	hidnplayr	1762	call tcp_cancel_timers
		1763	call socket_is_disconnected
3545	hidnplayr	1764
6476	hidnplayr	1765	;-----------------------------------------------------------------------------------
3545	hidnplayr	1766	.fin_timed:
6476	hidnplayr	1767	; (re)start the 2 MSL timer
3545	hidnplayr	1768	mov [ebx + TCP_SOCKET.timer_timed_wait], 2 * TCP_time_MSL
3600	hidnplayr	1769	or [ebx + TCP_SOCKET.timer_flags], timer_flag_wait
3545	hidnplayr	1770
6476	hidnplayr	1771	;-----------------------------------------------------------------------------------
		1772	;
		1773	; Finally, drop the segment
		1774	;
		1775	;-----------------------------------------------------------------------------------
3545	hidnplayr	1776
4347	hidnplayr	1777	.final_processing:
6908	ashmew2	1778	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Final processing\n"
4347	hidnplayr	1779
		1780	push ebx
		1781	lea ecx, [ebx + SOCKET.mutex]
		1782	call mutex_unlock
		1783	pop eax
		1784
		1785	test [temp_bits], TCP_BIT_NEEDOUTPUT
		1786	jnz .need_output
		1787
		1788	test [eax + TCP_SOCKET.t_flags], TF_ACKNOW
5133	hidnplayr	1789	jz .done
6908	ashmew2	1790	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: ACK now!\n"
4347	hidnplayr	1791
		1792	.need_output:
6908	ashmew2	1793	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: need output\n"
6011	hidnplayr	1794	call tcp_output
4347	hidnplayr	1795
5133	hidnplayr	1796	.done:
6908	ashmew2	1797	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: dumping\n"
4347	hidnplayr	1798
6011	hidnplayr	1799	call net_buff_free
4347	hidnplayr	1800	jmp .loop
		1801
6476	hidnplayr	1802	;-----------------------------------------------------------------------------------
		1803	;
		1804	; Drop segment, reply with an RST segment when needed
		1805	;
		1806	;-----------------------------------------------------------------------------------
4347	hidnplayr	1807
6476	hidnplayr	1808	;-----------------------------------------------------------------------------------
3545	hidnplayr	1809	.drop_after_ack:
6908	ashmew2	1810	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Drop after ACK\n"
3545	hidnplayr	1811
		1812	push edx ebx
		1813	lea ecx, [ebx + SOCKET.mutex]
		1814	call mutex_unlock
		1815	pop eax edx
		1816
		1817	test [edx + TCP_header.Flags], TH_RST
5133	hidnplayr	1818	jnz .done
3545	hidnplayr	1819
		1820	or [eax + TCP_SOCKET.t_flags], TF_ACKNOW
		1821	jmp .need_output
		1822
6476	hidnplayr	1823	;-----------------------------------------------------------------------------------
3545	hidnplayr	1824	.drop_with_reset:
6908	ashmew2	1825	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Drop with reset\n"
3545	hidnplayr	1826
		1827	push ebx edx
		1828	lea ecx, [ebx + SOCKET.mutex]
		1829	call mutex_unlock
		1830	pop edx ebx
		1831
		1832	test [edx + TCP_header.Flags], TH_RST
5133	hidnplayr	1833	jnz .done
3545	hidnplayr	1834
6011	hidnplayr	1835	; TODO: if its a multicast/broadcast, also drop
3545	hidnplayr	1836
		1837	test [edx + TCP_header.Flags], TH_ACK
		1838	jnz .respond_ack
		1839
		1840	test [edx + TCP_header.Flags], TH_SYN
		1841	jnz .respond_syn
5133	hidnplayr	1842	jmp .done
3545	hidnplayr	1843
		1844	.respond_ack:
		1845	push ebx
		1846	mov cl, TH_RST
6011	hidnplayr	1847	call tcp_respond
3545	hidnplayr	1848	pop ebx
		1849	jmp .destroy_new_socket
		1850
		1851	.respond_syn:
		1852	push ebx
		1853	mov cl, TH_RST + TH_ACK
6011	hidnplayr	1854	call tcp_respond
3545	hidnplayr	1855	pop ebx
		1856	jmp .destroy_new_socket
		1857
5133	hidnplayr	1858	;-----------------------------------------
		1859	; The connection has no associated socket
		1860
3647	hidnplayr	1861	.no_socket:
		1862	pusha
		1863	mov ecx, socket_mutex
		1864	call mutex_unlock
		1865	popa
		1866
3545	hidnplayr	1867	.respond_seg_reset:
		1868	test [edx + TCP_header.Flags], TH_RST
		1869	jnz .drop_no_socket
		1870
6011	hidnplayr	1871	; TODO: if its a multicast/broadcast, also drop
3545	hidnplayr	1872
		1873	test [edx + TCP_header.Flags], TH_ACK
		1874	jnz .respond_seg_ack
		1875
		1876	test [edx + TCP_header.Flags], TH_SYN
		1877	jnz .respond_seg_syn
		1878
		1879	jmp .drop_no_socket
		1880
		1881	.respond_seg_ack:
		1882	mov cl, TH_RST
5842	hidnplayr	1883	xor ebx, ebx ; FIXME: find a way to get the receiving device ptr
6011	hidnplayr	1884	call tcp_respond_segment
3545	hidnplayr	1885	jmp .drop_no_socket
		1886
		1887	.respond_seg_syn:
		1888	mov cl, TH_RST + TH_ACK
5842	hidnplayr	1889	xor ebx, ebx ; FIXME: find a way to get the receiving device ptr
6011	hidnplayr	1890	call tcp_respond_segment
3545	hidnplayr	1891	jmp .drop_no_socket
		1892
5133	hidnplayr	1893	;------------------------------------------------
		1894	; Unlock socket mutex and prepare to drop segment
3545	hidnplayr	1895
		1896	.drop:
6908	ashmew2	1897	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Dropping segment\n"
3545	hidnplayr	1898
		1899	pusha
		1900	lea ecx, [ebx + SOCKET.mutex]
		1901	call mutex_unlock
		1902	popa
		1903
5133	hidnplayr	1904	;--------------------------------------------
		1905	; Destroy the newly created socket if needed
		1906
3545	hidnplayr	1907	.destroy_new_socket:
4347	hidnplayr	1908	test [temp_bits], TCP_BIT_DROPSOCKET
3545	hidnplayr	1909	jz .drop_no_socket
		1910
		1911	mov eax, ebx
6011	hidnplayr	1912	call socket_free
3545	hidnplayr	1913
5133	hidnplayr	1914	;------------------
		1915	; Drop the segment
		1916
3545	hidnplayr	1917	.drop_no_socket:
6908	ashmew2	1918	DEBUGF DEBUG_NETWORK_VERBOSE, "TCP_input: Drop (no socket)\n"
3545	hidnplayr	1919
6011	hidnplayr	1920	call net_buff_free
3545	hidnplayr	1921	jmp .loop
4339	hidnplayr	1922
		1923	endp

Subversion Repositories Kolibri OS

(root)/kernel/trunk/network/tcp_input.inc – Rev 6908