WebSVN – Kolibri OS – Blame – /kernel/branches/net/network/tcp_input.inc

Rev	Author	Line No.	Line
1763	hidnplayr	1	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
		2	;; ;;
		3	;; Copyright (C) KolibriOS team 2004-2011. All rights reserved. ;;
		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	;; ;;
		10	;; Based on the code of 4.4BSD ;;
		11	;; ;;
		12	;; GNU GENERAL PUBLIC LICENSE ;;
		13	;; Version 2, June 1991 ;;
		14	;; ;;
		15	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
		16
		17	$Revision: 2315 $
		18
1733	hidnplayr	19	;-----------------------------------------------------------------
		20	;
		21	; TCP_input:
		22	;
		23	; IN: [esp] = ptr to buffer
		24	; [esp+4] = buffer size
		25	; ebx = ptr to device struct
		26	; ecx = segment size
2310	hidnplayr	27	; esi = ptr to TCP segment
2308	hidnplayr	28	; edi = ptr to ipv4 source address, followed by ipv4 dest address
1733	hidnplayr	29	;
		30	; OUT: /
		31	;
		32	;-----------------------------------------------------------------
1830	hidnplayr	33
1733	hidnplayr	34	align 4
		35	TCP_input:
		36
2309	hidnplayr	37	DEBUGF 1,"TCP_input size=%u\n", ecx
1733	hidnplayr	38
2310	hidnplayr	39	and [esi + TCP_header.DataOffset], 0xf0 ; Calculate TCP segment header size (throwing away unused reserved bits in TCP header)
		40	shr [esi + TCP_header.DataOffset], 2
		41	cmp [esi + TCP_header.DataOffset], sizeof.TCP_header ; Now see if it's at least the size of a standard TCP header
2309	hidnplayr	42	jb .drop_not_locked ; If not, drop the packet
1733	hidnplayr	43
		44	;-------------------------------
		45	; Now, re-calculate the checksum
		46
2310	hidnplayr	47	push ecx esi
		48	pushw [esi + TCP_header.Checksum]
		49	mov [esi + TCP_header.Checksum], 0
2308	hidnplayr	50	TCP_checksum (edi), (edi+4)
		51	pop cx ; previous checksum
		52	cmp cx, dx
2309	hidnplayr	53	pop edx ecx
2308	hidnplayr	54	jnz .drop_not_locked
1733	hidnplayr	55
2309	hidnplayr	56	DEBUGF 1,"Checksum ok\n"
1733	hidnplayr	57
2310	hidnplayr	58	movzx eax, [edx + TCP_header.DataOffset]
		59	sub ecx, eax ; substract TCP header size from total segment size
2309	hidnplayr	60	jb .drop_not_locked ; If total segment size is less then the advertised header size, drop packet
2308	hidnplayr	61	DEBUGF 1,"we got %u bytes of data\n", ecx
1733	hidnplayr	62
		63	;-----------------------------------------------------------------------------------------
		64	; Check if this packet has a timestamp option (We do it here so we can process it quickly)
		65
2310	hidnplayr	66	cmp eax, sizeof.TCP_header + 12 ; Timestamp option is 12 bytes
2308	hidnplayr	67	jb .no_timestamp
		68	je .is_ok
1733	hidnplayr	69
2309	hidnplayr	70	cmp byte [edx + sizeof.TCP_header + 12], TCP_OPT_EOL ; end of option list
2308	hidnplayr	71	jne .no_timestamp
1733	hidnplayr	72
		73	.is_ok:
2309	hidnplayr	74	test [edx + TCP_header.Flags], TH_SYN ; SYN flag must not be set
2308	hidnplayr	75	jnz .no_timestamp
1733	hidnplayr	76
2309	hidnplayr	77	cmp dword [edx + sizeof.TCP_header], 0x0101080a ; Timestamp header
2308	hidnplayr	78	jne .no_timestamp
1733	hidnplayr	79
2308	hidnplayr	80	DEBUGF 1,"timestamp ok\n"
1733	hidnplayr	81
2308	hidnplayr	82	; TODO: Parse the option
		83	; TODO: Set a Bit in the TCP to tell all options are parsed
1733	hidnplayr	84
		85	.no_timestamp:
		86
		87	;-------------------------------------------
		88	; Convert Big-endian values to little endian
		89
2308	hidnplayr	90	ntohd [edx + TCP_header.SequenceNumber]
		91	ntohd [edx + TCP_header.AckNumber]
1733	hidnplayr	92
2308	hidnplayr	93	ntohw [edx + TCP_header.Window]
		94	ntohw [edx + TCP_header.UrgentPointer]
		95	ntohw [edx + TCP_header.SourcePort]
		96	ntohw [edx + TCP_header.DestinationPort]
1733	hidnplayr	97
		98	;------------------------------------------------------------
1831	hidnplayr	99	; Next thing to do is find the TCPS (thus, the socket pointer)
1733	hidnplayr	100
		101	; IP Packet TCP Destination Port = local Port
		102	; (IP Packet SenderAddress = Remote IP) OR (Remote IP = 0)
2309	hidnplayr	103	; (IP Packet TCP Source Port = remote Port) OR (remote Port = 0)
1733	hidnplayr	104
2308	hidnplayr	105	mov ebx, net_sockets
2309	hidnplayr	106	mov si, [edx + TCP_header.DestinationPort]
1733	hidnplayr	107
		108	.socket_loop:
2308	hidnplayr	109	mov ebx, [ebx + SOCKET.NextPtr]
		110	or ebx, ebx
		111	jz .drop_with_reset_not_locked
1733	hidnplayr	112
2308	hidnplayr	113	cmp [ebx + SOCKET.Domain], AF_INET4
		114	jne .socket_loop
1733	hidnplayr	115
2308	hidnplayr	116	cmp [ebx + SOCKET.Protocol], IP_PROTO_TCP
		117	jne .socket_loop
1733	hidnplayr	118
2309	hidnplayr	119	cmp [ebx + TCP_SOCKET.LocalPort], si
2308	hidnplayr	120	jne .socket_loop
1733	hidnplayr	121
2308	hidnplayr	122	mov eax, [ebx + IP_SOCKET.RemoteIP]
		123	cmp eax, [edi] ; Ipv4 source addres
		124	je @f
		125	test eax, eax
		126	jnz .socket_loop
1733	hidnplayr	127	@@:
		128
2308	hidnplayr	129	mov ax, [ebx + TCP_SOCKET.RemotePort]
		130	cmp [edx + TCP_header.SourcePort] , ax
		131	je .found_socket
		132	test ax, ax
		133	jnz .socket_loop
2309	hidnplayr	134	.found_socket: ; ebx now contains the socketpointer
2308	hidnplayr	135	DEBUGF 1,"Socket ptr: %x\n", ebx
1733	hidnplayr	136
		137
		138	;----------------------------
		139	; Check if socket isnt closed
		140
2308	hidnplayr	141	cmp [ebx + TCP_SOCKET.t_state], TCPS_CLOSED
		142	je .drop_not_locked
1733	hidnplayr	143
		144	;----------------
		145	; Lock the socket
		146
2308	hidnplayr	147	cmp [ebx + SOCKET.lock], 0
		148	jne .drop_not_locked ;;; HACK ! HACK ! dirty fucking HACK ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1830	hidnplayr	149
2308	hidnplayr	150	add ebx, SOCKET.lock
		151	DEBUGF 1,"lock: %x\n", [ebx]
		152	call wait_mutex
		153	sub ebx, SOCKET.lock
1733	hidnplayr	154
2308	hidnplayr	155	DEBUGF 1,"Socket locked\n"
1733	hidnplayr	156
		157	;---------------------------------------
		158	; unscale the window into a 32 bit value
		159
2308	hidnplayr	160	movzx eax, [edx + TCP_header.Window]
		161	push ecx
		162	mov cl, [ebx + TCP_SOCKET.SND_SCALE]
		163	shl eax, cl
		164	mov dword [edx + TCP_header.Window], eax ; word after window is checksum, we dont need checksum anymore
		165	pop ecx
1733	hidnplayr	166
		167	;-----------------------------------
		168	; Is this socket a listening socket?
		169
2308	hidnplayr	170	test [ebx + SOCKET.options], SO_ACCEPTCON
		171	jz .no_listening_socket
1733	hidnplayr	172
2308	hidnplayr	173	DEBUGF 1,"Accepting new connection\n"
1838	hidnplayr	174
2308	hidnplayr	175	mov [ebx + SOCKET.lock], 0
2315	hidnplayr	176	push ecx edx esi edi ;;;
2308	hidnplayr	177	call SOCKET_fork
2315	hidnplayr	178	pop edi esi edx ecx
1838	hidnplayr	179
2308	hidnplayr	180	test eax, eax
		181	jz .drop
1733	hidnplayr	182
2308	hidnplayr	183	push dword [edi + 4] ; Ipv4 destination addres
		184	pop [eax + IP_SOCKET.LocalIP]
1733	hidnplayr	185
2308	hidnplayr	186	push [edx + TCP_header.DestinationPort]
		187	pop [eax + TCP_SOCKET.LocalPort]
1733	hidnplayr	188
2308	hidnplayr	189	mov [eax + TCP_SOCKET.t_state], TCPS_LISTEN
1733	hidnplayr	190
1838	hidnplayr	191	; mov [ebx + SOCKET.lock], 0
2308	hidnplayr	192	mov ebx, eax
1733	hidnplayr	193
2308	hidnplayr	194	jmp .LISTEN
1838	hidnplayr	195
1733	hidnplayr	196	.no_listening_socket:
		197
		198	;-------------------------------------
		199	; Reset idle timer and keepalive timer
		200
2308	hidnplayr	201	mov [ebx + TCP_SOCKET.t_idle], 0
		202	mov [ebx + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval
1733	hidnplayr	203
		204	;--------------------
		205	; Process TCP options
		206
2310	hidnplayr	207	movzx eax, [edx + TCP_header.DataOffset]
		208	cmp eax, sizeof.TCP_header ; Does header contain any options?
2308	hidnplayr	209	je .no_options
1733	hidnplayr	210
2308	hidnplayr	211	DEBUGF 1,"Segment has options\n"
1733	hidnplayr	212
2308	hidnplayr	213	cmp [ebx + TCP_SOCKET.t_state], TCPS_LISTEN ; no options when in listen state
		214	jz .not_uni_xfer ; also no header prediction
1733	hidnplayr	215
2309	hidnplayr	216	add eax, edx
2308	hidnplayr	217	lea esi, [edx + sizeof.TCP_header]
1733	hidnplayr	218
		219	.opt_loop:
2308	hidnplayr	220	cmp esi, eax ; are we scanning outside of header?
		221	jae .no_options
1733	hidnplayr	222
2308	hidnplayr	223	cmp byte [esi], TCP_OPT_EOL ; end of option list?
		224	jz .no_options
1733	hidnplayr	225
2308	hidnplayr	226	cmp byte [esi], TCP_OPT_NOP ; nop ?
		227	jz .opt_nop
1733	hidnplayr	228
2308	hidnplayr	229	cmp byte [esi], TCP_OPT_MAXSEG
		230	je .opt_maxseg
1733	hidnplayr	231
2308	hidnplayr	232	cmp byte [esi], TCP_OPT_WINDOW
		233	je .opt_window
1733	hidnplayr	234
2308	hidnplayr	235	cmp byte [esi], TCP_OPT_TIMESTAMP
		236	je .opt_timestamp
1733	hidnplayr	237
2308	hidnplayr	238	jmp .no_options ; If we reach here, some unknown options were received, skip them all!
1733	hidnplayr	239
		240	.opt_nop:
2308	hidnplayr	241	inc edi
		242	jmp .opt_loop
1733	hidnplayr	243
		244	.opt_maxseg:
2308	hidnplayr	245	cmp byte [esi+1], 4
		246	jne .no_options ; error occured, ignore all options!
1733	hidnplayr	247
2308	hidnplayr	248	test [edx + TCP_header.Flags], TH_SYN
		249	jz @f
1733	hidnplayr	250
2308	hidnplayr	251	movzx eax, word[esi+2]
		252	rol ax, 8
		253	DEBUGF 1,"Maxseg: %u\n", ax
1733	hidnplayr	254
2308	hidnplayr	255	mov [ebx + TCP_SOCKET.t_maxseg], eax
1733	hidnplayr	256
		257	@@:
2308	hidnplayr	258	add edi, 4
		259	jmp .opt_loop
1733	hidnplayr	260
		261
		262	.opt_window:
2308	hidnplayr	263	cmp byte [esi+1], 3
		264	jne .no_options
1733	hidnplayr	265
2308	hidnplayr	266	test [edx + TCP_header.Flags], TH_SYN
		267	jz @f
1733	hidnplayr	268
2308	hidnplayr	269	DEBUGF 1,"Got window option\n"
1733	hidnplayr	270
2308	hidnplayr	271	;;;;;
1733	hidnplayr	272	@@:
2308	hidnplayr	273	add edi, 3
		274	jmp .opt_loop
1733	hidnplayr	275
		276
		277	.opt_timestamp:
2308	hidnplayr	278	cmp byte [esi+1], 10
		279	jne .no_options
1733	hidnplayr	280
2308	hidnplayr	281	DEBUGF 1,"Got timestamp option\n"
1733	hidnplayr	282
2308	hidnplayr	283	;;;;;
1733	hidnplayr	284
2308	hidnplayr	285	add esi, 10
		286	jmp .opt_loop
1733	hidnplayr	287
		288	.no_options:
		289
		290
		291
		292
		293
		294
		295	;-----------------------------------------------------------------------
		296	; Time to do some header prediction (Original Principle by Van Jacobson)
		297
		298	; There are two common cases for an uni-directional data transfer.
		299	;
		300	; General rule: the packets has no control flags, is in-sequence,
		301	; window width didnt change and we're not retransmitting.
		302	;
		303	; Second rules:
		304	; - If the length is 0 and the ACK moved forward, we're the sender side of the transfer.
		305	; In this case we'll free the ACK'ed data and notify higher levels that we have free space in buffer
		306	;
		307	; - If the length is not 0 and the ACK didn't move, we're the receiver side of the transfer.
		308	; If the packets are in order (data queue is empty), add the data to the socket buffer and request a delayed ACK
		309
2308	hidnplayr	310	cmp [ebx + TCP_SOCKET.t_state], TCPS_ESTABLISHED
		311	jnz .not_uni_xfer
1733	hidnplayr	312
2308	hidnplayr	313	test [edx + TCP_header.Flags], TH_SYN + TH_FIN + TH_RST + TH_URG
		314	jnz .not_uni_xfer
1733	hidnplayr	315
2308	hidnplayr	316	test [edx + TCP_header.Flags], TH_ACK
		317	jz .not_uni_xfer
1733	hidnplayr	318
2308	hidnplayr	319	mov eax, [edx + TCP_header.SequenceNumber]
		320	cmp eax, [ebx + TCP_SOCKET.RCV_NXT]
		321	jne .not_uni_xfer
1733	hidnplayr	322
2308	hidnplayr	323	mov eax, dword [edx + TCP_header.Window]
		324	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		325	jne .not_uni_xfer
1733	hidnplayr	326
2308	hidnplayr	327	mov eax, [ebx + TCP_SOCKET.SND_NXT]
		328	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		329	jne .not_uni_xfer
1733	hidnplayr	330
		331	;---------------------------------------
		332	; check if we are sender in the uni-xfer
		333
		334	; If the following 4 conditions are all true, this segment is a pure ACK.
		335	;
		336	; - The segment contains no data.
2308	hidnplayr	337	test ecx, ecx
		338	jnz .not_sender
1733	hidnplayr	339
		340	; - The congestion window is greater than or equal to the current send window.
		341	; 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.
2308	hidnplayr	342	mov eax, [ebx + TCP_SOCKET.SND_CWND]
		343	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		344	jb .not_uni_xfer
1733	hidnplayr	345
		346	; - The acknowledgment field in the segment is less than or equal to the maximum sequence number sent.
2308	hidnplayr	347	mov eax, [edx + TCP_header.AckNumber]
		348	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		349	ja .not_uni_xfer
1733	hidnplayr	350
		351	; - The acknowledgment field in the segment is greater than the largest unacknowledged sequence number.
2308	hidnplayr	352	sub eax, [ebx + TCP_SOCKET.SND_UNA]
		353	jbe .not_uni_xfer
1733	hidnplayr	354
2308	hidnplayr	355	DEBUGF 1,"Header prediction: we are sender\n"
1733	hidnplayr	356
		357	;---------------------------------
		358	; Packet is a pure ACK, process it
		359
		360	; Update RTT estimators
		361
1763	hidnplayr	362	;;; TODO
		363
1733	hidnplayr	364	; Delete acknowledged bytes from send buffer
2308	hidnplayr	365	pusha
		366	mov ecx, eax
		367	lea eax, [ebx + STREAM_SOCKET.snd]
		368	call SOCKET_ring_free
		369	popa
1733	hidnplayr	370
		371	; update window pointers
2308	hidnplayr	372	mov eax, [edx + TCP_header.AckNumber]
		373	mov [ebx + TCP_SOCKET.SND_UNA], eax
1733	hidnplayr	374
		375	; Stop retransmit timer
2308	hidnplayr	376	mov [ebx + TCP_SOCKET.timer_retransmission], 0
1733	hidnplayr	377
		378	; Awaken waiting processes
2308	hidnplayr	379	mov [ebx + SOCKET.lock], 0
		380	mov eax, ebx
		381	call SOCKET_notify_owner
1733	hidnplayr	382
1763	hidnplayr	383	; Generate more output
2308	hidnplayr	384	call TCP_output
1733	hidnplayr	385
2308	hidnplayr	386	jmp .drop_not_locked
1763	hidnplayr	387
1733	hidnplayr	388	;-------------------------------------------------
		389	; maybe we are the receiver in the uni-xfer then..
		390
		391	.not_sender:
		392	; - The amount of data in the segment is greater than 0 (data count is in ecx)
		393
		394	; - The acknowledgment field equals the largest unacknowledged sequence number. This means no data is acknowledged by this segment.
2308	hidnplayr	395	mov eax, [edx + TCP_header.AckNumber]
		396	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
		397	jne .not_uni_xfer
1733	hidnplayr	398
		399	; - The reassembly list of out-of-order segments for the connection is empty (seg_next equals tp).
		400
		401	;;; TODO
		402
2308	hidnplayr	403	jnz .not_uni_xfer
1733	hidnplayr	404
		405	; Complete processing of received data
		406
2308	hidnplayr	407	DEBUGF 1,"header prediction: we are receiver\nreceiving %u bytes of data\n", ecx
1733	hidnplayr	408
2308	hidnplayr	409	add [ebx + TCP_SOCKET.RCV_NXT], ecx ; Update sequence number with number of bytes we have copied
1763	hidnplayr	410
2308	hidnplayr	411	movzx esi, [edx + TCP_header.DataOffset]
		412	add esi, edx
		413	lea eax, [ebx + STREAM_SOCKET.rcv]
		414	call SOCKET_ring_write ; Add the data to the socket buffer
1733	hidnplayr	415
2308	hidnplayr	416	mov eax, ebx
		417	call SOCKET_notify_owner
1733	hidnplayr	418
2308	hidnplayr	419	or [ebx + TCP_SOCKET.t_flags], TF_DELACK ; Set delayed ack flag
1733	hidnplayr	420
2308	hidnplayr	421	jmp .drop
1733	hidnplayr	422
		423
		424
		425
		426
		427
		428	;--------------------------------------------------
		429	; Header prediction failed, do it the slow way
		430
		431	.not_uni_xfer:
		432
2308	hidnplayr	433	DEBUGF 1,"Header prediction failed\n"
1733	hidnplayr	434
		435	; Calculate receive window size
		436
2305	hidnplayr	437	; mov eax, [ebx + STREAM_SOCKET.rcv + RING_BUFFER.size]
		438	; neg eax
		439	; add eax, SOCKETBUFFSIZE
		440	; mov edx, [ebx + TCP_SOCKET.RCV_ADV]
		441	; sub edx, [ebx + TCP_SOCKET.RCV_NXT]
		442	; cmp eax, edx
		443	; jae @f
		444	; mov eax, edx
		445	; @@:
1733	hidnplayr	446
2308	hidnplayr	447	cmp [ebx + TCP_SOCKET.t_state], TCPS_LISTEN
		448	je .LISTEN
1733	hidnplayr	449
2308	hidnplayr	450	cmp [ebx + TCP_SOCKET.t_state], TCPS_SYN_SENT
		451	je .SYN_SENT
1733	hidnplayr	452
2308	hidnplayr	453	jmp .NOT_LISTEN_OR_SYN_SENT
1733	hidnplayr	454
		455
		456
		457	;-------------
		458	; Passive Open
		459
		460	align 4
		461	.LISTEN:
		462
2308	hidnplayr	463	DEBUGF 1,"TCP state: listen\n"
1733	hidnplayr	464
2308	hidnplayr	465	test [edx + TCP_header.Flags], TH_RST ;;; TODO: kill new socket on error
		466	jnz .drop
1733	hidnplayr	467
2308	hidnplayr	468	test [edx + TCP_header.Flags], TH_ACK
		469	jnz .drop_with_reset
1733	hidnplayr	470
2308	hidnplayr	471	test [edx + TCP_header.Flags], TH_SYN
		472	jz .drop
1733	hidnplayr	473
		474	;;; TODO: check if it's a broadcast or multicast, and drop if so
		475
2308	hidnplayr	476	push dword [edi + 4] ; Ipv4 destination addres
		477	pop [ebx + IP_SOCKET.RemoteIP]
1733	hidnplayr	478
2308	hidnplayr	479	push [edx + TCP_header.SourcePort]
		480	pop [ebx + TCP_SOCKET.RemotePort]
1733	hidnplayr	481
2308	hidnplayr	482	push [edx + TCP_header.SequenceNumber]
		483	pop [ebx + TCP_SOCKET.IRS]
1733	hidnplayr	484
2308	hidnplayr	485	push [TCP_sequence_num] ;;;;;
		486	add [TCP_sequence_num], 64000 / 2
		487	pop [ebx + TCP_SOCKET.ISS]
1733	hidnplayr	488
2308	hidnplayr	489	push [ebx + TCP_SOCKET.ISS]
		490	pop [ebx + TCP_SOCKET.SND_NXT]
1733	hidnplayr	491
2308	hidnplayr	492	TCP_sendseqinit ebx
		493	TCP_rcvseqinit ebx
1733	hidnplayr	494
2308	hidnplayr	495	mov [ebx + TCP_SOCKET.t_state], TCPS_SYN_RECEIVED
		496	mov [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
		497	mov [ebx + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval ;;;; macro
1838	hidnplayr	498
2308	hidnplayr	499	lea eax, [ebx + STREAM_SOCKET.snd]
		500	call SOCKET_ring_create
1733	hidnplayr	501
2308	hidnplayr	502	lea eax, [ebx + STREAM_SOCKET.rcv]
		503	call SOCKET_ring_create
1733	hidnplayr	504
1838	hidnplayr	505	;;; call SOCKET_notify_owner
1733	hidnplayr	506
2308	hidnplayr	507	jmp .trim_then_step6
		508
1733	hidnplayr	509
		510
		511
		512
		513
		514
		515
		516
1838	hidnplayr	517
1733	hidnplayr	518	;------------
		519	; Active Open
		520
		521	align 4
		522	.SYN_SENT:
		523
2308	hidnplayr	524	DEBUGF 1,"TCP state: syn_sent\n"
1733	hidnplayr	525
2308	hidnplayr	526	test [edx + TCP_header.Flags], TH_ACK
		527	jz @f
1733	hidnplayr	528
2308	hidnplayr	529	mov eax, [edx + TCP_header.AckNumber]
		530	cmp eax, [ebx + TCP_SOCKET.ISS]
		531	jbe .drop_with_reset
1733	hidnplayr	532
2308	hidnplayr	533	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		534	ja .drop_with_reset
1733	hidnplayr	535	@@:
		536
2308	hidnplayr	537	test [edx + TCP_header.Flags], TH_RST
		538	jz @f
1733	hidnplayr	539
2308	hidnplayr	540	test [edx + TCP_header.Flags], TH_ACK
		541	jz .drop
1733	hidnplayr	542
2308	hidnplayr	543	mov eax, ebx
		544	mov ebx, ECONNREFUSED
		545	call TCP_drop
1733	hidnplayr	546
2308	hidnplayr	547	jmp .drop
1733	hidnplayr	548	@@:
		549
2308	hidnplayr	550	test [edx + TCP_header.Flags], TH_SYN
		551	jz .drop
1733	hidnplayr	552
		553	; at this point, segment seems to be valid
		554
2308	hidnplayr	555	test [edx + TCP_header.Flags], TH_ACK
		556	jz .no_syn_ack
1733	hidnplayr	557
		558	; now, process received SYN in response to an active open
		559
2308	hidnplayr	560	mov eax, [edx + TCP_header.AckNumber]
		561	mov [ebx + TCP_SOCKET.SND_UNA], eax
		562	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		563	jbe @f
		564	mov [ebx + TCP_SOCKET.SND_NXT], eax
1733	hidnplayr	565	@@:
		566
		567	.no_syn_ack:
		568
2308	hidnplayr	569	mov [ebx + TCP_SOCKET.timer_retransmission], 0 ; disable retransmission
1733	hidnplayr	570
2308	hidnplayr	571	push [edx + TCP_header.SequenceNumber]
		572	pop [ebx + TCP_SOCKET.IRS]
1733	hidnplayr	573
2308	hidnplayr	574	TCP_rcvseqinit ebx
1733	hidnplayr	575
2308	hidnplayr	576	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1733	hidnplayr	577
2308	hidnplayr	578	mov eax, [ebx + TCP_SOCKET.SND_UNA]
		579	cmp eax, [ebx + TCP_SOCKET.ISS]
		580	jbe .simultaneous_open
1733	hidnplayr	581
2308	hidnplayr	582	test [edx + TCP_header.Flags], TH_ACK
		583	jz .simultaneous_open
1733	hidnplayr	584
2308	hidnplayr	585	DEBUGF 1,"TCP: active open\n"
1733	hidnplayr	586
		587	;;; TODO: update stats
		588
		589	; set socket state to connected
		590
2308	hidnplayr	591	mov [ebx + SOCKET.state],1 ;;;; FIXME
1733	hidnplayr	592
2308	hidnplayr	593	mov [ebx + TCP_SOCKET.t_state], TCPS_ESTABLISHED
1733	hidnplayr	594
		595	;;; TODO: check if we should scale the connection (567-572)
		596	;;; TODO: update RTT estimators
		597
2308	hidnplayr	598	jmp .trim_then_step6
1733	hidnplayr	599
		600	.simultaneous_open:
		601
2308	hidnplayr	602	DEBUGF 1,"TCP: simultaneous open\n"
1733	hidnplayr	603	; We have received a syn but no ACK, so we are having a simultaneous open..
2308	hidnplayr	604	mov [ebx + TCP_SOCKET.t_state], TCPS_SYN_RECEIVED
1733	hidnplayr	605
		606
		607
		608
		609
		610
		611
		612	;-------------------------------------
		613	; Common processing for receipt of SYN
		614
		615	.trim_then_step6:
		616
2308	hidnplayr	617	inc [edx + TCP_header.SequenceNumber]
1733	hidnplayr	618
		619	;;; TODO: Drop any received data that follows receive window (590)
		620
2308	hidnplayr	621	mov eax, [edx + TCP_header.SequenceNumber]
		622	mov [ebx + TCP_SOCKET.RCV_UP], eax
		623	dec eax
		624	mov [ebx + TCP_SOCKET.SND_WL1], eax
1733	hidnplayr	625
2308	hidnplayr	626	jmp .ack_processed
1733	hidnplayr	627
		628
		629
		630
		631
		632
		633
		634
		635	.NOT_LISTEN_OR_SYN_SENT:
		636
2308	hidnplayr	637	DEBUGF 1,"Slow TCP input: not listen or syn_sent state\n"
1733	hidnplayr	638
		639	;--------------------------------------------
		640	; Protection Against Wrapped Sequence Numbers
		641
		642	; First, check if timestamp is present
		643
1763	hidnplayr	644	;;;; TODO 602
1733	hidnplayr	645
		646	; Then, check if at least some bytes of data are within window
		647
		648	;;;; TODO
		649
		650
		651
		652
		653
		654
		655
		656
		657	;----------------------------
		658	; trim any data not in window
		659
		660	; check for duplicate data at beginning of segment
		661
2308	hidnplayr	662	mov eax, [ebx + TCP_SOCKET.RCV_NXT]
		663	sub eax, [edx + TCP_header.SequenceNumber]
		664	jbe .no_duplicate
1733	hidnplayr	665
2308	hidnplayr	666	DEBUGF 1,"Uh oh.. %u bytes of duplicate data!\n", eax
1763	hidnplayr	667
2308	hidnplayr	668	test [edx + TCP_header.Flags], TH_SYN
		669	jz .no_dup_syn
1733	hidnplayr	670
		671	; remove duplicate syn
		672
2308	hidnplayr	673	and [edx + TCP_header.Flags], not (TH_SYN)
		674	inc [edx + TCP_header.SequenceNumber]
1733	hidnplayr	675
2308	hidnplayr	676	cmp [edx + TCP_header.UrgentPointer], 1
		677	jbe @f
		678	dec [edx + TCP_header.UrgentPointer]
		679	jmp .dup_syn
1733	hidnplayr	680	@@:
2308	hidnplayr	681	and [edx + TCP_header.Flags], not (TH_URG)
1838	hidnplayr	682	.dup_syn:
2308	hidnplayr	683	dec eax
1763	hidnplayr	684	.no_dup_syn:
1733	hidnplayr	685
		686	; eax holds number of bytes to drop
		687
		688	; Check for entire duplicate packet
		689
2308	hidnplayr	690	cmp eax, ecx
		691	jae .duplicate
1733	hidnplayr	692
2308	hidnplayr	693	DEBUGF 1,"Going to drop %u out of %u bytes\n", eax, ecx
1830	hidnplayr	694
1733	hidnplayr	695	;;; TODO: apply figure 28.30
		696
		697	; Check for duplicate FIN
		698
2308	hidnplayr	699	test [edx + TCP_header.Flags], TH_FIN
		700	jz @f
		701	inc ecx
		702	cmp eax, ecx
		703	dec ecx
		704	jne @f
1733	hidnplayr	705
2308	hidnplayr	706	mov eax, ecx
		707	and [edx + TCP_header.Flags], not TH_FIN
		708	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
		709	jmp .no_duplicate
1733	hidnplayr	710	@@:
		711
		712	; Handle the case when a bound socket connects to itself
		713	; Allow packets with a SYN and an ACKto continue with the processing
		714
		715	;-------------------------------------
		716	; Generate duplicate ACK if nescessary
		717
		718	; This code also handles simultaneous half-open or self-connects
		719
2308	hidnplayr	720	test eax, eax
		721	jnz .drop_after_ack
1733	hidnplayr	722
2308	hidnplayr	723	cmp [edx + TCP_header.Flags], TH_ACK
		724	jz .drop_after_ack
1733	hidnplayr	725
		726	.duplicate:
		727
2308	hidnplayr	728	DEBUGF 1,"Duplicate received\n"
1733	hidnplayr	729
		730	;----------------------------------------
		731	; Update statistics for duplicate packets
		732
		733	;;; TODO
		734
2308	hidnplayr	735	jmp .drop_after_ack
1733	hidnplayr	736
		737	.no_duplicate:
		738
		739	;-----------------------------------------------
		740	; Remove duplicate data and update urgent offset
		741
2308	hidnplayr	742	add [edx + TCP_header.SequenceNumber], eax
1733	hidnplayr	743
		744	;;; TODO
		745
2308	hidnplayr	746	sub [edx + TCP_header.UrgentPointer], ax
		747	ja @f
1733	hidnplayr	748
2308	hidnplayr	749	and [edx + TCP_header.Flags], not (TH_URG)
		750	mov [edx + TCP_header.UrgentPointer], 0
1733	hidnplayr	751	@@:
		752
		753	;--------------------------------------------------
		754	; Handle data that arrives after process terminates
		755
2308	hidnplayr	756	cmp [ebx + SOCKET.PID], 0
		757	ja @f
1733	hidnplayr	758
2308	hidnplayr	759	cmp [ebx + TCP_SOCKET.t_state], TCPS_CLOSE_WAIT
		760	jbe @f
1733	hidnplayr	761
2308	hidnplayr	762	test ecx, ecx
		763	jz @f
1733	hidnplayr	764
		765	;;; Close the socket
		766	;;; update stats
		767
2308	hidnplayr	768	jmp .drop_with_reset
1733	hidnplayr	769	@@:
		770
		771	;----------------------------------------
		772	; Remove data beyond right edge of window
		773
2308	hidnplayr	774	mov eax, [edx + TCP_header.SequenceNumber]
		775	add eax, ecx
		776	sub eax, [ebx + TCP_SOCKET.RCV_NXT]
		777	sub ax, [ebx + TCP_SOCKET.RCV_WND]
1733	hidnplayr	778
		779	; eax now holds the number of bytes to drop
		780
2308	hidnplayr	781	jbe .no_excess_data
1733	hidnplayr	782
		783	;;; TODO: update stats
		784
2308	hidnplayr	785	cmp eax, ecx
		786	jb .dont_drop_all
1733	hidnplayr	787
		788	;;; TODO 700-736
		789
		790	.dont_drop_all:
		791
		792	.no_excess_data:
		793
		794
		795
		796
		797
		798
		799
		800
		801	;-----------------
		802	; Record timestamp
		803
		804	;;; TODO 737-746
		805
		806
		807
		808
		809
		810	;------------------
		811	; Process RST flags
		812
2308	hidnplayr	813	test [edx + TCP_header.Flags], TH_RST
		814	jz .rst_skip
1733	hidnplayr	815
2308	hidnplayr	816	DEBUGF 1,"Got an RST flag"
1733	hidnplayr	817
2308	hidnplayr	818	mov eax, [ebx + TCP_SOCKET.t_state]
		819	shl eax, 2
		820	jmp dword [eax + .rst_sw_list]
1733	hidnplayr	821
		822	.rst_sw_list:
2308	hidnplayr	823	dd .rst_skip ;TCPS_CLOSED
		824	dd .rst_skip ;TCPS_LISTEN
		825	dd .rst_skip ;TCPS_SYN_SENT
		826	dd .econnrefused ;TCPS_SYN_RECEIVED
		827	dd .econnreset ;TCPS_ESTABLISHED
		828	dd .econnreset ;TCPS_CLOSE_WAIT
		829	dd .econnreset ;TCPS_FIN_WAIT_1
		830	dd .rst_close ;TCPS_CLOSING
		831	dd .rst_close ;TCPS_LAST_ACK
		832	dd .econnreset ;TCPS_FIN_WAIT_2
		833	dd .rst_close ;TCPS_TIMED_WAIT
1733	hidnplayr	834
		835	.econnrefused:
2308	hidnplayr	836	DEBUGF 1,"Connection refused"
1733	hidnplayr	837
2308	hidnplayr	838	mov [ebx + SOCKET.errorcode], ECONNREFUSED
		839	jmp .close
1733	hidnplayr	840
		841	.econnreset:
2308	hidnplayr	842	DEBUGF 1,"Connection reset"
1733	hidnplayr	843
2308	hidnplayr	844	mov [ebx + SOCKET.errorcode], ECONNRESET
1733	hidnplayr	845
1831	hidnplayr	846	.close:
2308	hidnplayr	847	DEBUGF 1,"Closing connection"
1733	hidnplayr	848
2308	hidnplayr	849	mov [ebx + TCP_SOCKET.t_state], TCPS_CLOSED
		850	;;; TODO: update stats
		851	mov eax, ebx
		852	call TCP_close
		853	jmp .drop
1733	hidnplayr	854
		855	.rst_close:
2308	hidnplayr	856	DEBUGF 1,"Closing with reset\n"
1733	hidnplayr	857
2308	hidnplayr	858	mov eax, ebx
		859	call TCP_close
		860	jmp .drop
1733	hidnplayr	861
		862
		863
		864
		865
		866
		867
1763	hidnplayr	868	.rst_skip:
1733	hidnplayr	869
1763	hidnplayr	870
1733	hidnplayr	871	;--------------------------------------
		872	; handle SYN-full and ACK-less segments
		873
2308	hidnplayr	874	test [edx + TCP_header.Flags], TH_SYN
		875	jz @f
1733	hidnplayr	876
2308	hidnplayr	877	mov eax, ebx
		878	mov ebx, ECONNRESET
		879	call TCP_drop
		880	jmp .drop_with_reset
1733	hidnplayr	881
2308	hidnplayr	882	test [edx + TCP_header.Flags], TH_ACK
		883	jz .drop
1733	hidnplayr	884	@@:
		885
		886
		887
		888
		889
		890
		891
		892	;---------------
		893	; ACK processing
		894
2308	hidnplayr	895	cmp [ebx + TCP_SOCKET.t_state], TCPS_SYN_RECEIVED
		896	jnz .no_syn_rcv
1733	hidnplayr	897
2308	hidnplayr	898	DEBUGF 1,"TCP state = syn received\n"
1733	hidnplayr	899
2308	hidnplayr	900	mov eax, [edx + TCP_header.AckNumber]
		901	cmp [ebx + TCP_SOCKET.SND_UNA], eax
		902	ja .drop_with_reset
		903	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		904	ja .drop_with_reset
1733	hidnplayr	905
2309	hidnplayr	906	;;; TODO: update stats
		907
2308	hidnplayr	908	mov eax, ebx
		909	call SOCKET_is_connected
		910	mov [ebx + TCP_SOCKET.t_state], TCPS_ESTABLISHED
1831	hidnplayr	911
		912	; Do window scaling?
		913
2308	hidnplayr	914	test [ebx + TCP_SOCKET.t_flags], TF_RCVD_SCALE
		915	jz @f
		916	test [ebx + TCP_SOCKET.t_flags], TF_REQ_SCALE
		917	jz @f
1831	hidnplayr	918
2309	hidnplayr	919	push word [ebx + TCP_SOCKET.requested_s_scale] ; Set send and receive scale factors to the received values
		920	pop word [ebx + TCP_SOCKET.SND_SCALE]
1831	hidnplayr	921	@@:
		922
2309	hidnplayr	923	;;; TODO: copy the data (if any) into the socket
1831	hidnplayr	924
2308	hidnplayr	925	mov eax, [edx + TCP_header.SequenceNumber]
		926	dec eax
		927	mov [ebx + TCP_SOCKET.SND_WL1], eax
		928	jmp .not_dup_ack
1831	hidnplayr	929
1733	hidnplayr	930	.no_syn_rcv:
		931
		932	; check for duplicate ACK
		933
2308	hidnplayr	934	mov eax, [edx + TCP_header.AckNumber]
		935	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
		936	ja .not_dup_ack
1733	hidnplayr	937
2308	hidnplayr	938	test ecx, ecx
		939	jnz .reset_dupacks
1733	hidnplayr	940
2308	hidnplayr	941	mov eax, dword [edx + TCP_header.Window]
		942	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		943	jne .reset_dupacks
1733	hidnplayr	944
2308	hidnplayr	945	DEBUGF 1,"Processing a duplicate ACK..\n"
1733	hidnplayr	946
2309	hidnplayr	947	cmp [ebx + TCP_SOCKET.timer_retransmission], 10000 ;;;; FIXME
2308	hidnplayr	948	ja @f
1733	hidnplayr	949
2308	hidnplayr	950	mov eax, [edx + TCP_header.AckNumber]
		951	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
		952	je .dup_ack
1763	hidnplayr	953
		954	@@:
2308	hidnplayr	955	mov [ebx + TCP_SOCKET.t_dupacks], 0
		956	jmp .not_dup_ack
1763	hidnplayr	957
		958	.dup_ack:
2308	hidnplayr	959	inc [ebx + TCP_SOCKET.t_dupacks]
		960	cmp [ebx + TCP_SOCKET.t_dupacks], TCP_re_xmit_thresh
		961	jne .no_re_xmit
1763	hidnplayr	962
2308	hidnplayr	963	push [ebx + TCP_SOCKET.SND_NXT] ; >>>>
1763	hidnplayr	964
2308	hidnplayr	965	mov eax, [ebx + TCP_SOCKET.SND_WND]
		966	cmp eax, [ebx + TCP_SOCKET.SND_CWND]
		967	cmovg eax, [ebx + TCP_SOCKET.SND_CWND]
		968	shr eax, 1
		969	push edx
		970	xor edx, edx
		971	div [ebx + TCP_SOCKET.t_maxseg]
		972	cmp eax, 2
		973	jae @f
		974	mov ax, 2
1763	hidnplayr	975	@@:
2308	hidnplayr	976	mul [ebx + TCP_SOCKET.t_maxseg]
		977	pop edx
		978	mov [ebx + TCP_SOCKET.SND_SSTHRESH], eax
1763	hidnplayr	979
2308	hidnplayr	980	mov [ebx + TCP_SOCKET.timer_retransmission], 0 ; turn off retransmission timer
		981	mov [ebx + TCP_SOCKET.t_rtt], 0
		982	mov eax, [edx + TCP_header.AckNumber]
		983	mov [ebx + TCP_SOCKET.SND_NXT], eax
		984	mov eax, [ebx + TCP_SOCKET.t_maxseg]
		985	mov [ebx + TCP_SOCKET.SND_CWND], eax
1763	hidnplayr	986
2308	hidnplayr	987	mov eax, ebx
		988	call TCP_output ; retransmit missing segment
1763	hidnplayr	989
2308	hidnplayr	990	push edx
		991	xor edx, edx
		992	mov eax, [ebx + TCP_SOCKET.t_maxseg]
		993	mul [ebx + TCP_SOCKET.t_dupacks]
		994	pop edx
		995	add eax, [ebx + TCP_SOCKET.SND_SSTHRESH]
		996	mov [ebx + TCP_SOCKET.SND_CWND], eax
1763	hidnplayr	997
2308	hidnplayr	998	pop eax ; <<<<
		999	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		1000	jb @f
		1001	mov [ebx + TCP_SOCKET.SND_NXT], eax
1763	hidnplayr	1002	@@:
		1003
2308	hidnplayr	1004	jmp .drop
1733	hidnplayr	1005
		1006
1763	hidnplayr	1007	.no_re_xmit:
2308	hidnplayr	1008	jbe .not_dup_ack
1733	hidnplayr	1009
2308	hidnplayr	1010	DEBUGF 1,"Increasing congestion window\n"
1733	hidnplayr	1011
2308	hidnplayr	1012	mov eax, [ebx + TCP_SOCKET.t_maxseg]
		1013	add [ebx + TCP_SOCKET.SND_CWND], eax
1733	hidnplayr	1014
2308	hidnplayr	1015	mov eax, ebx
		1016	call TCP_output
1733	hidnplayr	1017
2308	hidnplayr	1018	jmp .drop
1733	hidnplayr	1019
		1020
		1021
1763	hidnplayr	1022
		1023
		1024
		1025	.not_dup_ack:
		1026
1733	hidnplayr	1027	;-------------------------------------------------
		1028	; If the congestion window was inflated to account
		1029	; for the other side's cached packets, retract it
		1030
2308	hidnplayr	1031	mov eax, [ebx + TCP_SOCKET.SND_SSTHRESH]
		1032	cmp eax, [ebx + TCP_SOCKET.SND_CWND]
		1033	ja @f
		1034	cmp [ebx + TCP_SOCKET.t_dupacks], TCP_re_xmit_thresh
		1035	jbe @f
		1036	mov [ebx + TCP_SOCKET.SND_CWND], eax
1763	hidnplayr	1037	@@:
1733	hidnplayr	1038
2308	hidnplayr	1039	mov [ebx + TCP_SOCKET.t_dupacks], 0
1733	hidnplayr	1040
2308	hidnplayr	1041	mov eax, [edx + TCP_header.AckNumber]
		1042	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		1043	jbe @f
1733	hidnplayr	1044
2308	hidnplayr	1045	;;; TODO: update stats
		1046	jmp .drop_after_ack
1733	hidnplayr	1047
1763	hidnplayr	1048	@@:
1733	hidnplayr	1049
2308	hidnplayr	1050	mov edi, [edx + TCP_header.AckNumber]
		1051	sub edi, [ebx + TCP_SOCKET.SND_UNA] ; now we got the number of acked bytes in edi
1733	hidnplayr	1052
2308	hidnplayr	1053	;;; TODO: update stats
1733	hidnplayr	1054
		1055
2308	hidnplayr	1056	DEBUGF 1,"We have an acceptable ACK of %x bytes\n", esi
1763	hidnplayr	1057
		1058
		1059
		1060
		1061
		1062
1733	hidnplayr	1063	;------------------------------------------
		1064	; RTT measurements and retransmission timer
		1065
2308	hidnplayr	1066	;;;;; 912 - 926
1733	hidnplayr	1067
2308	hidnplayr	1068	mov [ebx + TCP_SOCKET.timer_retransmission], 0
1733	hidnplayr	1069
2308	hidnplayr	1070	mov eax, [ebx + TCP_SOCKET.SND_MAX]
		1071	cmp eax, [edx + TCP_header.AckNumber]
		1072	je .all_outstanding
		1073	mov [ebx + TCP_SOCKET.timer_retransmission], 120 ;;;; TODO: correct this value (use a macro for it)
1733	hidnplayr	1074	.all_outstanding:
		1075
		1076
		1077
		1078
		1079
		1080
		1081
		1082	;-------------------------------------------
		1083	; Open congestion window in response to ACKs
		1084
2308	hidnplayr	1085	mov esi, [ebx + TCP_SOCKET.SND_CWND]
		1086	mov eax, [ebx + TCP_SOCKET.t_maxseg]
1733	hidnplayr	1087
2308	hidnplayr	1088	cmp esi, [ebx + TCP_SOCKET.SND_SSTHRESH]
		1089	jbe @f
		1090	push edx
		1091	push eax
		1092	mul eax
		1093	div esi
		1094	pop edx
		1095	shr edx, 3
		1096	add eax, edx
		1097	pop edx
1763	hidnplayr	1098	@@:
1733	hidnplayr	1099
2308	hidnplayr	1100	add esi, eax
1733	hidnplayr	1101
2308	hidnplayr	1102	push ecx
		1103	mov cl, [ebx + TCP_SOCKET.SND_SCALE]
		1104	mov eax, TCP_max_win
		1105	shl eax, cl
		1106	pop ecx
1733	hidnplayr	1107
2308	hidnplayr	1108	cmp esi, eax
		1109	cmovg esi, eax
		1110	mov [ebx + TCP_SOCKET.SND_CWND], esi
1733	hidnplayr	1111
		1112
		1113
		1114
1763	hidnplayr	1115
		1116
		1117
1733	hidnplayr	1118	;------------------------------------------
		1119	; Remove acknowledged data from send buffer
		1120
2308	hidnplayr	1121	push ecx edx ebx
		1122	mov ecx, edi
		1123	lea eax, [ebx + STREAM_SOCKET.snd]
		1124	call SOCKET_ring_free
		1125	pop ebx
		1126	sub [ebx + TCP_SOCKET.SND_WND], ecx
		1127	pop edx ecx
1733	hidnplayr	1128
		1129	; Wake up process waiting on send buffer
		1130
2308	hidnplayr	1131	mov eax, ebx
		1132	call SOCKET_notify_owner
1733	hidnplayr	1133
1831	hidnplayr	1134	; Update TCPS
1733	hidnplayr	1135
2308	hidnplayr	1136	mov eax, [edx + TCP_header.AckNumber]
		1137	mov [ebx + TCP_SOCKET.SND_UNA], eax
1733	hidnplayr	1138
2308	hidnplayr	1139	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		1140	jb @f
		1141	mov [ebx + TCP_SOCKET.SND_NXT], eax
1733	hidnplayr	1142	@@:
		1143
		1144
2308	hidnplayr	1145	;; TODO: use zero flag as 'ourfinisacked'
1733	hidnplayr	1146
		1147
		1148
		1149
		1150	; General ACK handling complete
		1151	; Now do the state-specific ones
		1152
2308	hidnplayr	1153	mov eax, [ebx + TCP_SOCKET.t_state]
		1154	jmp dword [eax*4 + .ACK_sw_list]
1733	hidnplayr	1155
		1156	.ACK_sw_list:
2308	hidnplayr	1157	dd .ack_processed ;TCPS_CLOSED
		1158	dd .ack_processed ;TCPS_LISTEN
		1159	dd .ack_processed ;TCPS_SYN_SENT
		1160	dd .ack_processed ;TCPS_SYN_RECEIVED
		1161	dd .ack_processed ;TCPS_ESTABLISHED
		1162	dd .ack_processed ;TCPS_CLOSE_WAIT
		1163	dd .ack_fw1 ;TCPS_FIN_WAIT_1
		1164	dd .ack_c ;TCPS_CLOSING
		1165	dd .ack_la ;TCPS_LAST_ACK
		1166	dd .ack_processed ;TCPS_FIN_WAIT_2
		1167	dd .ack_tw ;TCPS_TIMED_WAIT
1733	hidnplayr	1168
		1169
1772	hidnplayr	1170	.ack_fw1:
2308	hidnplayr	1171	jz .ack_processed
1733	hidnplayr	1172
2308	hidnplayr	1173	test [ebx + SOCKET.state], SS_CANTRCVMORE
		1174	jnz @f
		1175	mov eax, ebx
		1176	call SOCKET_is_disconnected
1773	hidnplayr	1177	;;; mov [ebx + TCP_SOCKET.timer_timed_wait], TCP_time_max_idle
1772	hidnplayr	1178	@@:
1733	hidnplayr	1179
2308	hidnplayr	1180	mov [ebx + TCP_SOCKET.t_state], TCPS_FIN_WAIT_2
		1181	jmp .ack_processed
1733	hidnplayr	1182
		1183
1772	hidnplayr	1184	.ack_c:
2308	hidnplayr	1185	jz .ack_processed
1772	hidnplayr	1186
2308	hidnplayr	1187	mov [ebx + TCP_SOCKET.t_state], TCPS_TIMED_WAIT
		1188	mov eax, ebx
		1189	call TCP_cancel_timers
		1190	mov [ebx + TCP_SOCKET.timer_timed_wait], 2 * TCP_time_MSL
		1191	mov eax, ebx
		1192	call SOCKET_is_disconnected
		1193	jmp .ack_processed
1733	hidnplayr	1194
		1195
1772	hidnplayr	1196	.ack_la:
2308	hidnplayr	1197	jz .ack_processed
1733	hidnplayr	1198
1773	hidnplayr	1199
2308	hidnplayr	1200	mov eax, ebx
		1201	call TCP_close
		1202	jmp .drop
1733	hidnplayr	1203
		1204
1772	hidnplayr	1205	.ack_tw:
2308	hidnplayr	1206	mov [ebx + TCP_SOCKET.timer_timed_wait], 2 * TCP_time_MSL
		1207	jmp .drop_after_ack
1733	hidnplayr	1208
		1209
1772	hidnplayr	1210
		1211
		1212
		1213
		1214
2308	hidnplayr	1215	.reset_dupacks: ; We got a new ACK, reset duplicate ACK counter
1733	hidnplayr	1216
2308	hidnplayr	1217	mov [ebx + TCP_SOCKET.t_dupacks], 0
1733	hidnplayr	1218
2308	hidnplayr	1219	.ack_processed: ; (step 6)
1733	hidnplayr	1220
2308	hidnplayr	1221	DEBUGF 1,"ACK processed\n"
1733	hidnplayr	1222
		1223	;----------------------------------------------
		1224	; check if we need to update window information
		1225
2308	hidnplayr	1226	test [edx + TCP_header.Flags], TH_ACK
		1227	jz .no_window_update
1733	hidnplayr	1228
2308	hidnplayr	1229	mov eax, [ebx + TCP_SOCKET.SND_WL1]
		1230	cmp eax, [edx + TCP_header.SequenceNumber]
		1231	jb .update_window
		1232	ja @f
1733	hidnplayr	1233
2308	hidnplayr	1234	mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1235	cmp eax, [edx + TCP_header.AckNumber]
		1236	jb .update_window
		1237	ja .no_window_update
1733	hidnplayr	1238	@@:
		1239
2308	hidnplayr	1240	mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1241	cmp eax, [edx + TCP_header.AckNumber]
		1242	jne .no_window_update
1733	hidnplayr	1243
2309	hidnplayr	1244	mov eax, dword [edx + TCP_header.Window]
2308	hidnplayr	1245	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		1246	jbe .no_window_update
1733	hidnplayr	1247
		1248	.update_window:
		1249
2308	hidnplayr	1250	DEBUGF 1,"Updating window\n"
1733	hidnplayr	1251
		1252	; Keep track of pure window updates
		1253
		1254	; test ecx, ecx
		1255	; jz @f
		1256	;
		1257	; mov eax, [ebx + TCP_SOCKET.SND_WL2]
2305	hidnplayr	1258	; cmp eax, [edx + TCP_header.AckNumber]
1733	hidnplayr	1259	; jne @f
		1260	;
		1261	; ;; mov eax, tiwin
		1262	; cmp eax, [ebx + TCP_SOCKET.SND_WND]
2300	hidnplayr	1263	; jbe @f
1733	hidnplayr	1264	;
		1265	; ;;; update stats
		1266	;
		1267	; @@:
		1268
2308	hidnplayr	1269	mov eax, dword [edx + TCP_header.Window]
		1270	cmp eax, [ebx + TCP_SOCKET.max_sndwnd]
		1271	jbe @f
		1272	mov [ebx + TCP_SOCKET.max_sndwnd], eax
1733	hidnplayr	1273	@@:
2308	hidnplayr	1274	mov [ebx + TCP_SOCKET.SND_WND], eax
1733	hidnplayr	1275
2308	hidnplayr	1276	push [edx + TCP_header.SequenceNumber]
		1277	pop [ebx + TCP_SOCKET.SND_WL1]
1733	hidnplayr	1278
2308	hidnplayr	1279	push [edx + TCP_header.AckNumber]
		1280	pop [ebx + TCP_SOCKET.SND_WL2]
1733	hidnplayr	1281
2308	hidnplayr	1282	;;; needoutput = 1
1733	hidnplayr	1283
		1284	.no_window_update:
		1285
		1286
		1287
		1288
		1289
		1290
		1291
		1292	;-----------------
		1293	; process URG flag
		1294
2308	hidnplayr	1295	test [edx + TCP_header.Flags], TH_URG
		1296	jz .not_urgent
1733	hidnplayr	1297
2308	hidnplayr	1298	cmp [edx + TCP_header.UrgentPointer], 0
		1299	jz .not_urgent
1733	hidnplayr	1300
2308	hidnplayr	1301	cmp [ebx + TCP_SOCKET.t_state], TCPS_TIMED_WAIT
		1302	je .not_urgent
1733	hidnplayr	1303
		1304	; Ignore bogus urgent offsets
		1305
2308	hidnplayr	1306	;;; 1040-1050
1733	hidnplayr	1307
2308	hidnplayr	1308	movzx eax, [edx + TCP_header.UrgentPointer]
		1309	add eax, [ebx + STREAM_SOCKET.rcv + RING_BUFFER.size]
		1310	cmp eax, SOCKET_MAXDATA
		1311	jbe .not_urgent
1733	hidnplayr	1312
2308	hidnplayr	1313	mov [edx + TCP_header.UrgentPointer], 0
		1314	and [edx + TCP_header.Flags], not (TH_URG)
		1315	jmp .do_data
1733	hidnplayr	1316
		1317	.not_urgent:
		1318
		1319	; processing of received urgent pointer
		1320
2308	hidnplayr	1321	;;; TODO (1051-1093)
1733	hidnplayr	1322
		1323
		1324
		1325
		1326
		1327
		1328
		1329
		1330	;--------------------------------
		1331	; process the data in the segment
		1332
		1333	.do_data:
		1334
2308	hidnplayr	1335	DEBUGF 1,"TCP: do data (%u)\n", ecx
1733	hidnplayr	1336
2308	hidnplayr	1337	test [edx + TCP_header.Flags], TH_FIN
		1338	jnz .process_fin
1733	hidnplayr	1339
2308	hidnplayr	1340	cmp [ebx + TCP_SOCKET.t_state], TCPS_FIN_WAIT_1
		1341	jae .dont_do_data
1733	hidnplayr	1342
2308	hidnplayr	1343	test ecx, ecx
		1344	jz .final_processing
1733	hidnplayr	1345
2308	hidnplayr	1346	DEBUGF 1,"Processing data in segment\n"
1733	hidnplayr	1347
		1348	;; TODO: check if data is in sequence !
		1349
2308	hidnplayr	1350	movzx esi, [edx + TCP_header.DataOffset]
		1351	add esi, edx
1733	hidnplayr	1352
2308	hidnplayr	1353	or [ebx + TCP_SOCKET.t_flags], TF_DELACK
		1354	add [ebx + TCP_SOCKET.RCV_NXT], ecx
1733	hidnplayr	1355
2308	hidnplayr	1356	lea eax, [ebx + STREAM_SOCKET.rcv]
		1357	call SOCKET_ring_write
1733	hidnplayr	1358
2308	hidnplayr	1359	mov eax, ebx
		1360	call SOCKET_notify_owner
1733	hidnplayr	1361
2308	hidnplayr	1362	jmp .final_processing
1733	hidnplayr	1363
		1364
		1365	.dont_do_data:
		1366
		1367
		1368
		1369
		1370
		1371
		1372
		1373	;---------------
		1374	; FIN processing
		1375
		1376	.process_fin:
		1377
2308	hidnplayr	1378	DEBUGF 1,"Processing FIN\n"
1733	hidnplayr	1379
2308	hidnplayr	1380	cmp [ebx + TCP_SOCKET.t_state], TCPS_CLOSE_WAIT
		1381	je .not_first_fin
		1382	cmp [ebx + TCP_SOCKET.t_state], TCPS_CLOSING
		1383	je .not_first_fin
		1384	cmp [ebx + TCP_SOCKET.t_state], TCPS_FIN_WAIT_2
		1385	je .not_first_fin
1774	hidnplayr	1386
2308	hidnplayr	1387	DEBUGF 1,"First FIN for this connection\n"
1774	hidnplayr	1388
2308	hidnplayr	1389	mov eax, ebx
		1390	call SOCKET_cant_recv_more
1774	hidnplayr	1391
2308	hidnplayr	1392	mov [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
		1393	inc [ebx + TCP_SOCKET.RCV_NXT]
1774	hidnplayr	1394
		1395	.not_first_fin:
2308	hidnplayr	1396	mov eax, [ebx + TCP_SOCKET.t_state]
		1397	shl eax, 2
		1398	jmp dword [eax + .FIN_sw_list]
1733	hidnplayr	1399
		1400	.FIN_sw_list:
2308	hidnplayr	1401	dd .no_fin ;TCPS_CLOSED
		1402	dd .no_fin ;TCPS_LISTEN
		1403	dd .no_fin ;TCPS_SYN_SENT
		1404	dd .fin_syn_est ;TCPS_SYN_RECEIVED
		1405	dd .fin_syn_est ;TCPS_ESTABLISHED
		1406	dd .no_fin ;TCPS_CLOSE_WAIT
		1407	dd .fin_wait1 ;TCPS_FIN_WAIT_1
		1408	dd .no_fin ;TCPS_CLOSING
		1409	dd .no_fin ;TCPS_LAST_ACK
		1410	dd .fin_wait2 ;TCPS_FIN_WAIT_2
		1411	dd .fin_timed ;TCPS_TIMED_WAIT
1733	hidnplayr	1412
		1413	.fin_syn_est:
		1414
2308	hidnplayr	1415	mov [ebx + TCP_SOCKET.t_state], TCPS_CLOSE_WAIT
		1416	jmp .no_fin
1733	hidnplayr	1417
		1418	.fin_wait1:
		1419
2308	hidnplayr	1420	mov [ebx + TCP_SOCKET.t_state], TCPS_CLOSING
		1421	jmp .no_fin
1733	hidnplayr	1422
		1423	.fin_wait2:
		1424
2308	hidnplayr	1425	mov [ebx + TCP_SOCKET.t_state], TCPS_TIMED_WAIT
		1426	mov eax, ebx
		1427	call TCP_cancel_timers
		1428	mov [ebx + TCP_SOCKET.timer_timed_wait], 2 * TCP_time_MSL
		1429	call SOCKET_is_disconnected
		1430	jmp .no_fin
1733	hidnplayr	1431
		1432	.fin_timed:
2308	hidnplayr	1433	mov [ebx + TCP_SOCKET.timer_timed_wait], 2 * TCP_time_MSL
		1434	jmp .no_fin
1733	hidnplayr	1435
		1436	.no_fin:
		1437
		1438
		1439
		1440
		1441
		1442
		1443
		1444
		1445	;-----------------
		1446	; Final processing
		1447
		1448	.final_processing:
		1449
2308	hidnplayr	1450	DEBUGF 1,"Final processing\n"
1733	hidnplayr	1451
2308	hidnplayr	1452	;;; if debug enabled, output packet
1733	hidnplayr	1453
2308	hidnplayr	1454	;test needoutput, needoutput
		1455	;jz .dumpit
1733	hidnplayr	1456
2308	hidnplayr	1457	test [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
		1458	jz .dumpit
1733	hidnplayr	1459
2308	hidnplayr	1460	DEBUGF 1,"ACK now!\n"
1733	hidnplayr	1461
2308	hidnplayr	1462	push ebx
		1463	mov eax, ebx
		1464	call TCP_output
		1465	pop ebx
1733	hidnplayr	1466
		1467	.dumpit:
		1468
2308	hidnplayr	1469	mov [ebx + SOCKET.lock], 0
1733	hidnplayr	1470
2308	hidnplayr	1471	call kernel_free
		1472	add esp, 4
		1473	ret
1733	hidnplayr	1474
		1475
		1476
		1477
		1478
		1479
		1480
		1481	;------------------------------------------
		1482	; Generate an ACK, droping incoming segment
		1483
		1484	align 4
		1485	.drop_after_ack:
		1486
2308	hidnplayr	1487	DEBUGF 1,"Drop after ACK\n"
1733	hidnplayr	1488
2308	hidnplayr	1489	test [edx + TCP_header.Flags], TH_RST
		1490	jnz .drop
1733	hidnplayr	1491
2308	hidnplayr	1492	and [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1733	hidnplayr	1493
2308	hidnplayr	1494	mov [ebx + SOCKET.lock], 0
1733	hidnplayr	1495
2308	hidnplayr	1496	push ebx
1838	hidnplayr	1497	; mov cl, TH_ACK
		1498	; call TCP_respond_socket
2308	hidnplayr	1499	mov eax, ebx
		1500	call TCP_output
		1501	pop ebx
1733	hidnplayr	1502
2308	hidnplayr	1503	call kernel_free
		1504	add esp, 4
		1505	ret
1733	hidnplayr	1506
		1507
		1508
		1509
		1510
		1511
		1512
		1513
		1514	;-------------------------------------------
		1515	; Generate an RST, dropping incoming segment
		1516
		1517	align 4
		1518	.drop_with_reset:
		1519
2308	hidnplayr	1520	mov [ebx + SOCKET.lock], 0
1733	hidnplayr	1521
		1522	.drop_with_reset_not_locked:
		1523
2308	hidnplayr	1524	DEBUGF 1,"Drop with reset\n"
1733	hidnplayr	1525
2308	hidnplayr	1526	test [edx + TCP_header.Flags], TH_RST
		1527	jnz .drop
1733	hidnplayr	1528
2308	hidnplayr	1529	;;; if its a multicast/broadcast, also drop
1733	hidnplayr	1530
2308	hidnplayr	1531	test [edx + TCP_header.Flags], TH_ACK
		1532	jnz .respond_ack
1733	hidnplayr	1533
2308	hidnplayr	1534	test [edx + TCP_header.Flags], TH_SYN
		1535	jnz .respond_syn
1733	hidnplayr	1536
2308	hidnplayr	1537	call kernel_free
		1538	add esp, 4
		1539	ret
1733	hidnplayr	1540
		1541	.respond_ack:
		1542
2308	hidnplayr	1543	push ebx
		1544	mov cl, TH_RST
		1545	call TCP_respond_socket
		1546	pop ebx
1733	hidnplayr	1547
2308	hidnplayr	1548	jmp .destroy_new_socket
1733	hidnplayr	1549
		1550
		1551	.respond_syn:
		1552
2308	hidnplayr	1553	push ebx
		1554	mov cl, TH_RST + TH_ACK
		1555	call TCP_respond_socket
		1556	pop ebx
1733	hidnplayr	1557
2308	hidnplayr	1558	jmp .destroy_new_socket
1733	hidnplayr	1559
		1560
		1561
		1562
		1563
		1564
		1565
		1566	;-----
		1567	; Drop
		1568
		1569	align 4
		1570	.drop:
		1571
2308	hidnplayr	1572	mov [ebx + SOCKET.lock], 0
1733	hidnplayr	1573
		1574	.drop_not_locked:
		1575
2308	hidnplayr	1576	DEBUGF 1,"Dropping packet\n"
1733	hidnplayr	1577
2308	hidnplayr	1578	;;;; If debugging options are enabled, output the packet somwhere
1733	hidnplayr	1579
		1580	.destroy_new_socket:
		1581
2308	hidnplayr	1582	;;;; kill the newly created socket
1733	hidnplayr	1583
2308	hidnplayr	1584	call kernel_free
		1585	add esp, 4
		1586	ret

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(root)/kernel/branches/net/network/tcp_input.inc – Rev 2315