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

Rev	Author	Line No.	Line
1196	hidnplayr	1	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
		2	;; ;;
1514	hidnplayr	3	;; Copyright (C) KolibriOS team 2004-2010. All rights reserved. ;;
1196	hidnplayr	4	;; Distributed under terms of the GNU General Public License ;;
		5	;; ;;
		6	;; TCP.INC ;;
		7	;; ;;
		8	;; Part of the tcp/ip network stack for KolibriOS ;;
		9	;; ;;
1514	hidnplayr	10	;; Written by hidnplayr@kolibrios.org ;;
1196	hidnplayr	11	;; ;;
1514	hidnplayr	12	;; Based on the code of 4.4BSD ;;
		13	;; ;;
1196	hidnplayr	14	;; GNU GENERAL PUBLIC LICENSE ;;
		15	;; Version 2, June 1991 ;;
		16	;; ;;
		17	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
1159	hidnplayr	18
1206	hidnplayr	19	$Revision: 1533 $
1159	hidnplayr	20
1514	hidnplayr	21	; Socket states
		22	TCB_CLOSED equ 0
		23	TCB_LISTEN equ 1
		24	TCB_SYN_SENT equ 2
		25	TCB_SYN_RECEIVED equ 3
		26	TCB_ESTABLISHED equ 4
		27	TCB_CLOSE_WAIT equ 5
		28	TCB_FIN_WAIT_1 equ 6
		29	TCB_CLOSING equ 7
		30	TCB_LAST_ACK equ 8
		31	TCB_FIN_WAIT_2 equ 9
		32	TCB_TIMED_WAIT equ 10
1196	hidnplayr	33
1514	hidnplayr	34	; Socket Flags
		35	TF_ACKNOW equ 1 shl 0 ; ack peer immediately
		36	TF_DELACK equ 1 shl 1 ; ack, but try to delay it
		37	TF_NODELAY equ 1 shl 2 ; don't delay packets to coalesce
		38	TF_NOOPT equ 1 shl 3 ; don't use tcp options
		39	TF_SENTFIN equ 1 shl 4 ; have sent FIN
		40	TF_REQ_SCALE equ 1 shl 5 ; have/will request window scaling
		41	TF_RCVD_SCALE equ 1 shl 6 ; other side has requested scaling
		42	TF_REQ_TSTMP equ 1 shl 7 ; have/will request timestamps
		43	TF_RCVD_TSTMP equ 1 shl 8 ; a timestamp was received in SYN
		44	TF_SACK_PERMIT equ 1 shl 9 ; other side said I could SACK
1249	hidnplayr	45
1514	hidnplayr	46	; Segment flags
		47	TH_FIN equ 1 shl 0
		48	TH_SYN equ 1 shl 1
		49	TH_RST equ 1 shl 2
		50	TH_PUSH equ 1 shl 3
		51	TH_ACK equ 1 shl 4
		52	TH_URG equ 1 shl 5
1318	hidnplayr	53
1514	hidnplayr	54	; Segment header options
		55	TCP_OPT_EOL equ 0 ; End of option list.
		56	TCP_OPT_NOP equ 1 ; No-Operation.
		57	TCP_OPT_MAXSEG equ 2 ; Maximum Segment Size.
		58	TCP_OPT_WINDOW equ 3 ; window scale
		59	TCP_OPT_TIMESTAMP equ 8
		60
1519	hidnplayr	61	; Fundamental timer values
		62	TCP_time_MSL equ 47 ; max segment lifetime (30s)
		63	TCP_time_re_min equ 2 ; min retransmission (1,28s)
		64	TCP_time_re_max equ 100 ; max retransmission (64s)
		65	TCP_time_pers_min equ 8 ; min persist (5,12s)
		66	TCP_time_pers_max equ 94 ; max persist (60,16s)
		67	TCP_time_keep_init equ 118 ; connectione stablishment (75,52s)
		68	TCP_time_keep_idle equ 4608 ; idle time before 1st probe (2h)
		69	TCP_time_keep_interval equ 118 ; between probes when no response (75,52s)
		70	TCP_time_rtt_default equ 5 ; default Round Trip Time (3,2s)
		71
		72	; timer constants
		73	TCP_max_rxtshift equ 12 ; max retransmissions waiting for ACK
		74	TCP_max_keepcnt equ 8 ; max keepalive probes
		75
1529	hidnplayr	76	;
		77	TCP_max_winshift equ 14
		78	TCP_max_win equ 65535
1519	hidnplayr	79
1514	hidnplayr	80	struct TCP_segment
1159	hidnplayr	81	.SourcePort dw ?
		82	.DestinationPort dw ?
		83	.SequenceNumber dd ?
		84	.AckNumber dd ?
1196	hidnplayr	85	.DataOffset db ? ; DataOffset[0-3 bits] and Reserved[4-7]
		86	.Flags db ? ; Reserved[0-1 bits]\|URG\|ACK\|PSH\|RST\|SYN\|FIN
1159	hidnplayr	87	.Window dw ?
		88	.Checksum dw ?
		89	.UrgentPointer dw ?
1514	hidnplayr	90	.Data: ; ..or options
1159	hidnplayr	91	ends
		92
1274	hidnplayr	93	struct tcp_in_queue_entry
		94	.data_ptr dd ?
		95	.data_size dd ?
1514	hidnplayr	96	.offset dd ?
1274	hidnplayr	97	.size:
		98	ends
		99
		100	struct tcp_out_queue_entry
		101	.data_ptr dd ?
		102	.data_size dd ?
1514	hidnplayr	103
1274	hidnplayr	104	.size:
		105	ends
		106
1196	hidnplayr	107	align 4
		108	uglobal
1514	hidnplayr	109	TCP_segments_tx rd IP_MAX_INTERFACES
		110	TCP_segments_rx rd IP_MAX_INTERFACES
		111	TCP_bytes_rx rq IP_MAX_INTERFACES
		112	TCP_bytes_tx rq IP_MAX_INTERFACES
		113	TCP_sequence_num dd ?
1196	hidnplayr	114	endg
		115
		116
		117	;-----------------------------------------------------------------
		118	;
		119	; TCP_init
		120	;
		121	; This function resets all TCP variables
		122	;
		123	;-----------------------------------------------------------------
1529	hidnplayr	124	macro TCP_init {
1196	hidnplayr	125
		126	xor eax, eax
1514	hidnplayr	127	mov edi, TCP_segments_tx
		128	mov ecx, (6*IP_MAX_INTERFACES)
1196	hidnplayr	129	rep stosd
		130
1529	hidnplayr	131	pseudo_random eax
		132	mov [TCP_sequence_num], eax
1196	hidnplayr	133
1529	hidnplayr	134	}
1196	hidnplayr	135
		136
1519	hidnplayr	137	;----------------------
1196	hidnplayr	138	;
1159	hidnplayr	139	;
1519	hidnplayr	140	;----------------------
1529	hidnplayr	141	macro TCP_timer_160ms {
1159	hidnplayr	142
1529	hidnplayr	143	local .loop
		144	local .exit
		145
1514	hidnplayr	146	mov eax, net_sockets
		147	.loop:
		148	mov eax, [eax + SOCKET.NextPtr]
		149	or eax, eax
1159	hidnplayr	150	jz .exit
		151
1514	hidnplayr	152	cmp [eax + SOCKET.Type], IP_PROTO_TCP
		153	jne .loop
1249	hidnplayr	154
1519	hidnplayr	155	dec [eax + TCP_SOCKET.timer_ack]
1514	hidnplayr	156	jnz .loop
1159	hidnplayr	157
1519	hidnplayr	158	DEBUGF 1,"TCP ack for socket %x expired, time to piggyback!\n", eax
1159	hidnplayr	159
1519	hidnplayr	160	push eax
1529	hidnplayr	161	call TCP_respond_socket
1514	hidnplayr	162	pop eax
1159	hidnplayr	163
1519	hidnplayr	164	jmp .loop
1159	hidnplayr	165
		166	.exit:
1519	hidnplayr	167
1529	hidnplayr	168	}
1159	hidnplayr	169
		170
1519	hidnplayr	171	;-----------------------------------------------------------------
1159	hidnplayr	172	;
		173	;
1519	hidnplayr	174	;-----------------------------------------------------------------
1529	hidnplayr	175	macro TCP_timer_640ms {
1159	hidnplayr	176
1529	hidnplayr	177	local .loop
		178	local .exit
		179
1519	hidnplayr	180	; Update TCP sequence number
		181
1514	hidnplayr	182	add [TCP_sequence_num], 64000
1159	hidnplayr	183
1519	hidnplayr	184	; scan through all the active TCP sockets, decrementing ALL timers
		185	; timers do not have the chance to wrap because of the keepalive timer will kill the socket when it expires
1159	hidnplayr	186
1519	hidnplayr	187	mov eax, net_sockets
		188	.loop:
		189	mov eax, [eax + SOCKET.NextPtr]
		190	.check_only:
		191	or eax, eax
		192	jz .exit
1159	hidnplayr	193
1519	hidnplayr	194	cmp [eax + SOCKET.Type], IP_PROTO_TCP
		195	jne .loop
1159	hidnplayr	196
1529	hidnplayr	197	inc [eax + TCP_SOCKET.t_idle]
		198	dec [eax + TCP_SOCKET.timer_retransmission]
1519	hidnplayr	199	jnz .check_more2
1254	hidnplayr	200
1519	hidnplayr	201	DEBUGF 1,"socket %x: Retransmission timer expired\n", eax
1159	hidnplayr	202
1519	hidnplayr	203	push eax
		204	call TCP_output
		205	pop eax
1159	hidnplayr	206
1519	hidnplayr	207	.check_more2:
		208	dec [eax + TCP_SOCKET.timer_keepalive]
		209	jnz .check_more3
1159	hidnplayr	210
1519	hidnplayr	211	DEBUGF 1,"socket %x: Keepalive expired\n", eax
1159	hidnplayr	212
1519	hidnplayr	213	;;; TODO: check socket state and handle accordingly
1318	hidnplayr	214
1519	hidnplayr	215	.check_more3:
		216	dec [eax + TCP_SOCKET.timer_timed_wait]
		217	jnz .check_more5
		218
		219	DEBUGF 1,"socket %x: 2MSL timer expired\n", eax
		220
		221	.check_more5:
		222	dec [eax + TCP_SOCKET.timer_persist]
		223	jnz .loop
		224
		225	DEBUGF 1,"socket %x: persist timer expired\n", eax
		226
		227	jmp .loop
		228	.exit:
1529	hidnplayr	229	}
1519	hidnplayr	230
		231
1529	hidnplayr	232
		233
		234	macro TCP_checksum IP1, IP2 {
		235
		236	;-------------
		237	; Pseudoheader
		238
		239	; protocol type
		240	mov edx, IP_PROTO_TCP
		241
		242	; source address
1530	hidnplayr	243	add dl, byte [IP1+1]
		244	adc dh, byte [IP1+0]
		245	adc dl, byte [IP1+3]
		246	adc dh, byte [IP1+2]
1529	hidnplayr	247
		248	; destination address
1530	hidnplayr	249	adc dl, byte [IP2+1]
		250	adc dh, byte [IP2+0]
		251	adc dl, byte [IP2+3]
		252	adc dh, byte [IP2+2]
1529	hidnplayr	253
		254	; size
		255	adc dl, cl
		256	adc dh, ch
		257
		258	;---------------------
		259	; Real header and data
		260
		261	push esi
		262	call checksum_1
		263	call checksum_2
		264	pop esi
		265
		266	} ; returns in dx only
		267
		268
1533	hidnplayr	269	macro TCP_sendseqinit ptr {
1529	hidnplayr	270
1533	hidnplayr	271	push edi ;;;; i dont like this static use of edi
		272	mov edi, [ptr + TCP_SOCKET.ISS]
		273	mov [ptr + TCP_SOCKET.SND_UP], edi
		274	mov [ptr + TCP_SOCKET.SND_MAX], edi
		275	mov [ptr + TCP_SOCKET.SND_NXT], edi
		276	mov [ptr + TCP_SOCKET.SND_UNA], edi
		277	pop edi
		278
		279	}
		280
		281	macro TCP_rcvseqinit ptr {
		282
		283	push edi
		284	mov edi, [ptr + TCP_SOCKET.IRS]
		285	inc edi
		286	mov [ptr + TCP_SOCKET.RCV_NXT], edi
		287	mov [ptr + TCP_SOCKET.RCV_ADV], edi
		288	pop edi
		289
		290	}
		291
		292
		293
1249	hidnplayr	294	;-----------------------------------------------------------------
		295	;
1514	hidnplayr	296	; TCP_input:
1159	hidnplayr	297	;
1514	hidnplayr	298	; IN: [esp] = ptr to buffer
		299	; [esp+4] = buffer size
		300	; ebx = ptr to device struct
		301	; ecx = segment size
		302	; edx = ptr to TCP segment
1196	hidnplayr	303	;
1514	hidnplayr	304	; esi = ipv4 source address
		305	; edi = ipv4 dest address
		306	;
1196	hidnplayr	307	; OUT: /
		308	;
		309	;-----------------------------------------------------------------
1249	hidnplayr	310	align 4
1514	hidnplayr	311	TCP_input:
1159	hidnplayr	312
1529	hidnplayr	313	DEBUGF 1,"TCP_input size=%u\n", ecx
1514	hidnplayr	314	; Offset must be greater than or equal to the size of the standard TCP header (20) and less than or equal to the TCP length.
1254	hidnplayr	315
1514	hidnplayr	316	movzx eax, [edx + TCP_segment.DataOffset]
		317	and eax, 0xf0
1529	hidnplayr	318	shr al, 2
1514	hidnplayr	319
1529	hidnplayr	320	DEBUGF 1,"headersize=%u\n", eax
1514	hidnplayr	321
		322	cmp eax, 20
		323	jl .drop
		324
		325	;-------------------------------
		326	; Now, re-calculate the checksum
		327
1529	hidnplayr	328	push eax ecx edx
		329	pushw [edx + TCP_segment.Checksum]
		330	mov [edx + TCP_segment.Checksum], 0
		331	push esi edi
1514	hidnplayr	332	mov esi, edx
1530	hidnplayr	333	TCP_checksum (esp), (esp+4)
1529	hidnplayr	334	pop esi edi ; yes, swap them (we dont need dest addr)
		335	pop cx ; previous checksum
		336	cmp cx, dx
		337	pop edx ecx esi
1514	hidnplayr	338	jnz .drop
		339
		340	DEBUGF 1,"Checksum is correct\n"
		341
1529	hidnplayr	342	sub ecx, esi ; update packet size
		343	jl .drop
		344
1514	hidnplayr	345	;-----------------------------------------------------------------------------------------
		346	; Check if this packet has a timestamp option (We do it here so we can process it quickly)
		347
1529	hidnplayr	348	cmp esi, 20 + 12 ; Timestamp option is 12 bytes
1514	hidnplayr	349	jl .no_timestamp
		350	je .is_ok
		351
1529	hidnplayr	352	cmp byte [edx + TCP_segment.Data + 12], TCP_OPT_EOL ; end of option list
1514	hidnplayr	353	jne .no_timestamp
		354
		355	.is_ok:
		356	test [edx + TCP_segment.Flags], TH_SYN ; SYN flag must not be set
		357	jnz .no_timestamp
		358
		359	cmp dword [edx + TCP_segment.Data], 0x0101080a ; Timestamp header
		360	jne .no_timestamp
		361
		362	DEBUGF 1,"timestamp ok\n"
		363
1529	hidnplayr	364	; TODO: Parse the option
1514	hidnplayr	365	; TODO: Set a Bit in the TCP to tell all options are parsed
		366
		367	.no_timestamp:
		368
		369	;-------------------------------------------
		370	; Convert Big-endian values to little endian
		371
		372	ntohld [edx + TCP_segment.SequenceNumber]
		373	ntohld [edx + TCP_segment.AckNumber]
		374
		375	ntohlw [edx + TCP_segment.Window]
		376	ntohlw [edx + TCP_segment.UrgentPointer]
1529	hidnplayr	377	ntohlw [edx + TCP_segment.SourcePort]
		378	ntohlw [edx + TCP_segment.DestinationPort]
1514	hidnplayr	379
		380	;------------------------------------------------------------
		381	; Next thing to do is find the TCB (thus, the socket pointer)
		382
1274	hidnplayr	383	; IP Packet TCP Destination Port = local Port
1514	hidnplayr	384	; (IP Packet SenderAddress = Remote IP) OR (Remote IP = 0)
1318	hidnplayr	385	; (IP Packet TCP Source Port = remote Port) OR (remote Port = 0)
1159	hidnplayr	386
		387	mov ebx, net_sockets
		388
1249	hidnplayr	389	.socket_loop:
1514	hidnplayr	390	mov ebx, [ebx + SOCKET.NextPtr]
1159	hidnplayr	391	or ebx, ebx
1514	hidnplayr	392	jz .drop_with_reset
1159	hidnplayr	393
1514	hidnplayr	394	cmp [ebx + SOCKET.Type], IP_PROTO_TCP
1249	hidnplayr	395	jne .socket_loop
1159	hidnplayr	396
1514	hidnplayr	397	mov ax, [edx + TCP_segment.DestinationPort]
		398	cmp [ebx + TCP_SOCKET.LocalPort], ax
		399	jne .socket_loop
		400
		401	mov eax, [ebx + IP_SOCKET.RemoteIP]
1529	hidnplayr	402	cmp eax, edi ; sender IP
1249	hidnplayr	403	je @f
		404	test eax, eax
1514	hidnplayr	405	jnz .socket_loop
1249	hidnplayr	406	@@:
1159	hidnplayr	407
1514	hidnplayr	408	mov ax, [ebx + TCP_SOCKET.RemotePort]
		409	cmp [edx + TCP_segment.SourcePort] , ax
1274	hidnplayr	410	je .found_socket
1249	hidnplayr	411	test ax, ax
1254	hidnplayr	412	jnz .socket_loop
1274	hidnplayr	413	.found_socket:
1529	hidnplayr	414	DEBUGF 1,"Socket ptr: %x\n", ebx
1254	hidnplayr	415
1514	hidnplayr	416	; ebx now contains the pointer to the socket
1257	hidnplayr	417
1514	hidnplayr	418	;----------------------------
		419	; Check if socket isnt closed
		420
1529	hidnplayr	421	cmp [ebx + TCP_SOCKET.t_state], TCB_CLOSED
1514	hidnplayr	422	je .drop
		423
		424	;----------------
		425	; Lock the socket
		426
1529	hidnplayr	427	;; add ebx, SOCKET.lock ; TODO: figure out if we should lock now already
		428	;; call wait_mutex
		429	;; sub ebx, SOCKET.lock
1159	hidnplayr	430
1529	hidnplayr	431	DEBUGF 1,"Socket locked\n"
1159	hidnplayr	432
1529	hidnplayr	433	;----------------------------------------------------------------------------------------
		434	; unscale the window into a 32 bit value (notice that SND_SCALE must be initialised to 0)
		435
1514	hidnplayr	436	movzx eax, [edx + TCP_segment.Window]
1529	hidnplayr	437	push cx
		438	mov cl, [ebx + TCP_SOCKET.SND_SCALE]
1514	hidnplayr	439	shl eax, cl
1529	hidnplayr	440	pop cx
1514	hidnplayr	441
1529	hidnplayr	442	;;;; do something with eax
1514	hidnplayr	443
		444	;-----------------------------------
		445	; Is this socket a listening socket?
		446
1533	hidnplayr	447	test [ebx + SOCKET.options], SO_ACCEPTCON
1529	hidnplayr	448	; jnz .listening_socket ;;;;; TODO
1514	hidnplayr	449
1529	hidnplayr	450	;-------------------------------------
		451	; Reset idle timer and keepalive timer
1514	hidnplayr	452
1529	hidnplayr	453	mov [ebx + TCP_SOCKET.t_idle], 0
		454	mov [ebx + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval
1514	hidnplayr	455
1529	hidnplayr	456	;--------------------
		457	; Process TCP options
1514	hidnplayr	458
1529	hidnplayr	459	cmp esi, 20 ; esi is headersize
		460	je .no_options
1514	hidnplayr	461
1529	hidnplayr	462	DEBUGF 1,"Segment has options\n"
1514	hidnplayr	463
1530	hidnplayr	464	cmp [ebx + TCP_SOCKET.t_state], TCB_LISTEN ; no options when in listen state
1529	hidnplayr	465	jz .no_options
1514	hidnplayr	466
1529	hidnplayr	467	lea edi, [edx + TCP_segment.Data]
		468	lea eax, [edx + esi]
1514	hidnplayr	469
1529	hidnplayr	470	.opt_loop:
		471	cmp edi, eax
		472	jge .no_options
1514	hidnplayr	473
1529	hidnplayr	474	cmp byte [edi], TCP_OPT_EOL ; end of option list?
		475	jz .no_options
1514	hidnplayr	476
1529	hidnplayr	477	cmp byte [edi], TCP_OPT_NOP ; nop ?
		478	jz .opt_nop
1514	hidnplayr	479
1529	hidnplayr	480	cmp byte [edi], TCP_OPT_MAXSEG
		481	je .opt_maxseg
1514	hidnplayr	482
1529	hidnplayr	483	cmp byte [edi], TCP_OPT_WINDOW
		484	je .opt_window
1514	hidnplayr	485
1529	hidnplayr	486	cmp byte [edi], TCP_OPT_TIMESTAMP
		487	je .opt_timestamp
1514	hidnplayr	488
1529	hidnplayr	489	jmp .no_options ; If we reach here, some unknown options were received, skip them all!
1514	hidnplayr	490
1529	hidnplayr	491	.opt_nop:
		492	inc edi
		493	jmp .opt_loop
1514	hidnplayr	494
1529	hidnplayr	495	.opt_maxseg:
		496	cmp byte [edi+1], 4
		497	jne .no_options ; error occured, ignore all options!
1514	hidnplayr	498
1529	hidnplayr	499	test [edx + TCP_segment.Flags], TH_SYN
		500	jz @f
		501
1530	hidnplayr	502	movzx eax, word[edi+2]
		503	rol ax, 8
1533	hidnplayr	504	DEBUGF 1,"Maxseg: %u\n", ax
1529	hidnplayr	505
1530	hidnplayr	506	mov [ebx + TCP_SOCKET.t_maxseg], eax
		507
1529	hidnplayr	508	@@:
		509	add edi, 4
		510	jmp .opt_loop
		511
		512
		513	.opt_window:
		514	cmp byte [edi+1], 3
		515	jne .no_options
		516
		517	test [edx + TCP_segment.Flags], TH_SYN
		518	jz @f
		519
1533	hidnplayr	520	DEBUGF 1,"Got window option\n"
1529	hidnplayr	521
		522	;;;;;
		523	@@:
		524	add edi, 3
		525	jmp .opt_loop
		526
		527
		528	.opt_timestamp:
		529	cmp byte [edi+1], 10
		530	jne .no_options
		531
1533	hidnplayr	532	DEBUGF 1,"Got timestamp option\n"
1529	hidnplayr	533
		534	;;;;;
		535
		536	add edi, 10
		537	jmp .opt_loop
		538
		539	.no_options:
		540
1514	hidnplayr	541	;-----------------------------------------------------------------------
		542	; Time to do some header prediction (Original Principle by Van Jacobson)
		543
		544	; There are two common cases for an uni-directional data transfer.
		545	;
		546	; General rule: the packets has no control flags, is in-sequence,
		547	; window width didnt change and we're not retransmitting.
		548	;
		549	; Second rules:
		550	; - If the length is 0 and the ACK moved forward, we're the sender side of the transfer.
		551	; In this case we'll free the ACK'ed data and notify higher levels that we have free space in buffer
		552	;
		553	; - If the length is not 0 and the ACK didn't move, we're the receiver side of the transfer.
		554	; If the packets are in order (data queue is empty), add the data to the socket buffer and request a delayed ACK
		555
1529	hidnplayr	556	cmp [ebx + TCP_SOCKET.t_state], TCB_ESTABLISHED
1514	hidnplayr	557	jnz .not_uni_xfer
		558
1533	hidnplayr	559	DEBUGF 1,"1\n"
		560
1529	hidnplayr	561	test [edx + TCP_segment.Flags], TH_SYN + TH_FIN + TH_RST + TH_URG
1514	hidnplayr	562	jnz .not_uni_xfer
		563
1533	hidnplayr	564	DEBUGF 1,"2\n"
		565
1529	hidnplayr	566	test [edx + TCP_segment.Flags], TH_ACK
1514	hidnplayr	567	jz .not_uni_xfer
		568
1533	hidnplayr	569	DEBUGF 1,"3\n"
		570
1514	hidnplayr	571	mov eax, [edx + TCP_segment.SequenceNumber]
		572	cmp eax, [ebx + TCP_SOCKET.RCV_NXT]
		573	jne .not_uni_xfer
		574
1533	hidnplayr	575	DEBUGF 1,"4\n"
1514	hidnplayr	576
1533	hidnplayr	577	;; movzx eax, [edx + TCP_segment.Window] ;;;;; (should use pre-calculated value isntead: todo: figure out where to store it)
		578	;; cmp eax, [ebx + TCP_SOCKET.SND_WND]
		579	;; jne .not_uni_xfer
		580
		581	DEBUGF 1,"5\n"
		582
1514	hidnplayr	583	mov eax, [ebx + TCP_SOCKET.SND_NXT]
		584	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		585	jne .not_uni_xfer
		586
		587	;---------------------------------------
		588	; check if we are sender in the uni-xfer
		589
		590	; If the following 4 conditions are all true, this segment is a pure ACK.
		591	;
1529	hidnplayr	592	; - The segment contains no data.
		593	test ecx, ecx
1514	hidnplayr	594	jnz .not_sender
1274	hidnplayr	595
1529	hidnplayr	596	; - The congestion window is greater than or equal to the current send window.
1514	hidnplayr	597	; 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.
		598	mov eax, [ebx + TCP_SOCKET.SND_CWND]
		599	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		600	jl .not_uni_xfer
1318	hidnplayr	601
1529	hidnplayr	602	; - The acknowledgment field in the segment is less than or equal to the maximum sequence number sent.
		603	mov ecx, [edx + TCP_segment.AckNumber]
		604	cmp ecx, [ebx + TCP_SOCKET.SND_MAX]
		605	jg .not_uni_xfer
		606
		607	; - The acknowledgment field in the segment is greater than the largest unacknowledged sequence number.
		608	sub ecx, [ebx + TCP_SOCKET.SND_UNA]
		609	jle .not_uni_xfer
		610
1514	hidnplayr	611	DEBUGF 1,"Header prediction: we are sender\n"
1274	hidnplayr	612
1514	hidnplayr	613	;---------------------------------
		614	; Packet is a pure ACK, process it
1274	hidnplayr	615
1514	hidnplayr	616	; Update RTT estimators
1159	hidnplayr	617
1514	hidnplayr	618	; Delete acknowledged bytes from send buffer
1529	hidnplayr	619	; notice how ecx already holds number of bytes ack-ed
1254	hidnplayr	620
1533	hidnplayr	621	lea eax, [ebx + STREAM_SOCKET.snd]
1529	hidnplayr	622	call SOCKET_ring_free
		623
1514	hidnplayr	624	; Stop retransmit timer
1519	hidnplayr	625	mov [ebx + TCP_SOCKET.timer_ack], 0
1159	hidnplayr	626
1514	hidnplayr	627	; Awaken waiting processes
1519	hidnplayr	628	mov eax, ebx
		629	call SOCKET_notify_owner
1318	hidnplayr	630
1514	hidnplayr	631	; Generate more output
1519	hidnplayr	632	call TCP_output
1254	hidnplayr	633
1514	hidnplayr	634	jmp .drop
1159	hidnplayr	635
1514	hidnplayr	636	;-------------------------------------------------
		637	; maybe we are the receiver in the uni-xfer then..
		638
		639	.not_sender:
1529	hidnplayr	640	; - The amount of data in the segment is greater than 0 (data count is in ecx)
1514	hidnplayr	641
1529	hidnplayr	642	; - The acknowledgment field equals the largest unacknowledged sequence number. This means no data is acknowledged by this segment.
1514	hidnplayr	643	mov eax, [edx + TCP_segment.AckNumber]
		644	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
		645	jne .not_uni_xfer
		646
1529	hidnplayr	647	; - The reassembly list of out-of-order segments for the connection is empty (seg_next equals tp). ;;;;;;;
1514	hidnplayr	648
		649	jnz .not_uni_xfer
		650
		651	;-------------------------------------
		652	; Complete processing of received data
		653
		654	DEBUGF 1,"header prediction: we are receiver\nreceiving %u bytes of data\n", ecx
		655
1529	hidnplayr	656	add esi, edx
1533	hidnplayr	657	lea eax, [ebx + STREAM_SOCKET.rcv]
		658	call SOCKET_ring_write ; Add the data to the socket buffer
1514	hidnplayr	659
1533	hidnplayr	660	mov eax, ebx
		661	call SOCKET_notify_owner
		662
1529	hidnplayr	663	add [ebx + TCP_SOCKET.RCV_NXT], ecx ; Update sequence number with number of bytes we have copied
		664	or [ebx + TCP_SOCKET.t_flags], TF_DELACK ; Set delayed ack flag
1514	hidnplayr	665
		666	jmp .drop
		667
		668	;----------------------------------------------------
1529	hidnplayr	669	; Header prediction failed, doing it the slow way.. ;;;;; current implementation of header prediction destroys some regs (ecx) !!
1514	hidnplayr	670
		671	.not_uni_xfer:
		672
1533	hidnplayr	673	DEBUGF 1,"Header prediction failed\n" ; time to do it the "slow" way :)
1514	hidnplayr	674
		675	;------------------------------
		676	; Calculate receive window size
		677
		678	;;;;
		679
1529	hidnplayr	680	cmp [ebx + TCP_SOCKET.t_state], TCB_LISTEN
1514	hidnplayr	681	je .LISTEN
		682
1529	hidnplayr	683	cmp [ebx + TCP_SOCKET.t_state], TCB_SYN_SENT
1514	hidnplayr	684	je .SYN_SENT
		685
		686	;--------------------------------------------
		687	; Protection Against Wrapped Sequence Numbers
		688
1533	hidnplayr	689	; First, check if timestamp is present
1514	hidnplayr	690
		691	;;;; TODO
		692
		693	; Then, check if at least some bytes of data are within window
		694
		695	;;;; TODO
		696
		697	jmp .trim_then_step6
		698
1529	hidnplayr	699	;-------------
		700	; Passive Open
		701
1249	hidnplayr	702	align 4
1514	hidnplayr	703	.LISTEN:
1196	hidnplayr	704
1514	hidnplayr	705	DEBUGF 1,"TCP state: listen\n"
1159	hidnplayr	706
1514	hidnplayr	707	test [edx + TCP_segment.Flags], TH_RST
		708	jnz .drop
1159	hidnplayr	709
1514	hidnplayr	710	test [edx + TCP_segment.Flags], TH_ACK
		711	jnz .drop_with_reset
1159	hidnplayr	712
1514	hidnplayr	713	test [edx + TCP_segment.Flags], TH_SYN
		714	jz .drop
1159	hidnplayr	715
1533	hidnplayr	716	cmp esi, 0xffffff ; destination ip = 255.255.255.255 ?
		717	jz .drop
		718
1514	hidnplayr	719	; TODO: check if it's a broadcast or multicast, and drop if so
1159	hidnplayr	720
1529	hidnplayr	721	call SOCKET_fork
		722	jz .drop ; if we could not open a new connection, drop segment (;;;; should we send RST too?)
1514	hidnplayr	723
1529	hidnplayr	724	;-----------------------
		725	; Fill in some variables
1514	hidnplayr	726
1529	hidnplayr	727	add [TCP_sequence_num], 64000
1514	hidnplayr	728
1529	hidnplayr	729	push [edx + TCP_segment.SourcePort]
		730	pop [eax + TCP_SOCKET.RemotePort]
1514	hidnplayr	731
1529	hidnplayr	732	push [edx + TCP_segment.SequenceNumber]
		733	pop [eax + TCP_SOCKET.IRS]
1159	hidnplayr	734
1529	hidnplayr	735	push [eax + TCP_SOCKET.ISS]
		736	pop [eax + TCP_SOCKET.SND_NXT]
1159	hidnplayr	737
1529	hidnplayr	738	mov [eax + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		739	mov [eax + TCP_SOCKET.t_flags], TF_ACKNOW
		740	mov [eax + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval
1159	hidnplayr	741
1529	hidnplayr	742	mov ebx, eax
1514	hidnplayr	743	jmp .trim_then_step6
1159	hidnplayr	744
1254	hidnplayr	745
1529	hidnplayr	746	;------------
		747	; Active Open
1159	hidnplayr	748
1514	hidnplayr	749	align 4
		750	.SYN_SENT:
1281	hidnplayr	751
1514	hidnplayr	752	DEBUGF 1,"TCP state: syn_sent\n"
1159	hidnplayr	753
1514	hidnplayr	754	test [edx + TCP_segment.Flags], TH_ACK
		755	jz @f
1281	hidnplayr	756
1514	hidnplayr	757	mov eax, [edx + TCP_segment.AckNumber]
		758	cmp eax, [ebx + TCP_SOCKET.ISS]
		759	jle .drop_with_reset
1281	hidnplayr	760
1529	hidnplayr	761	; mov eax, [edx + TCP_segment.AckNumber]
1533	hidnplayr	762	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		763	jg .drop_with_reset
1514	hidnplayr	764	@@:
1281	hidnplayr	765
1514	hidnplayr	766	test [edx + TCP_segment.Flags], TH_RST
		767	jz @f
1281	hidnplayr	768
1514	hidnplayr	769	test [edx + TCP_segment.Flags], TH_ACK
		770	jz .drop
1281	hidnplayr	771
1514	hidnplayr	772	;tp = tcp_drop(tp, ECONNREFUSED)
1159	hidnplayr	773
1514	hidnplayr	774	jmp .drop
		775	@@:
1159	hidnplayr	776
1514	hidnplayr	777	test [edx + TCP_segment.Flags], TH_SYN
		778	jz .drop
1318	hidnplayr	779
1529	hidnplayr	780	; at this point, segment seems to be valid
		781
1514	hidnplayr	782	test [edx + TCP_segment.Flags], TH_ACK
1529	hidnplayr	783	jz .no_syn_ack
1514	hidnplayr	784
1529	hidnplayr	785	; now, process received SYN in response to an active open
		786
1514	hidnplayr	787	mov eax, [edx + TCP_segment.AckNumber]
		788	mov [ebx + TCP_SOCKET.SND_UNA], eax
		789	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		790	jle @f
		791	mov [ebx + TCP_SOCKET.SND_NXT], eax
1529	hidnplayr	792	@@:
1514	hidnplayr	793
1529	hidnplayr	794	.no_syn_ack:
1514	hidnplayr	795
1529	hidnplayr	796	mov [ebx + TCP_SOCKET.timer_retransmission], 0 ; disable retransmission
1514	hidnplayr	797
1529	hidnplayr	798	push [edx + TCP_segment.SequenceNumber]
		799	pop [ebx + TCP_SOCKET.IRS]
		800
1533	hidnplayr	801	TCP_rcvseqinit ebx
1529	hidnplayr	802
		803	mov [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
		804
		805	mov eax, [ebx + TCP_SOCKET.SND_UNA]
		806	cmp eax, [ebx + TCP_SOCKET.ISS]
		807	jle .simultaneous_open
		808
		809	test [edx + TCP_segment.Flags], TH_ACK
		810	jz .simultaneous_open
		811
		812	DEBUGF 1,"TCP: active open\n"
		813
		814	; TODO: update stats
1533	hidnplayr	815	; TODO: set general socket state to connected
1514	hidnplayr	816
		817	mov [ebx + TCP_SOCKET.t_state], TCB_ESTABLISHED
		818
		819	; TODO: check if we should scale the connection (567-572)
		820	; TODO: update RTT estimators
		821
1529	hidnplayr	822	jmp .trimthenstep6
1514	hidnplayr	823
1529	hidnplayr	824	.simultaneous_open:
1514	hidnplayr	825
1529	hidnplayr	826	DEBUGF 1,"TCP: simultaneous open\n"
1514	hidnplayr	827	; We have received a syn but no ACK, so we are having a simultaneous open..
		828	mov [ebx + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		829
		830	;-------------------------------------
		831	; Common processing for receipt of SYN
		832
		833	.trimthenstep6:
		834
		835	inc [edx + TCP_segment.SequenceNumber]
		836
		837	cmp cx, [ebx + TCP_SOCKET.RCV_WND]
		838	jle @f
		839
		840	movzx eax, cx
		841	sub ax, [ebx + TCP_SOCKET.RCV_WND]
		842	; TODO: 592
		843	mov cx, [ebx + TCP_SOCKET.RCV_WND]
		844	; TODO...
		845	@@:
		846	;;;;;
1529	hidnplayr	847	jmp .step6
1514	hidnplayr	848
		849
		850
		851
		852
1529	hidnplayr	853	.trim_then_step6:
1159	hidnplayr	854
1514	hidnplayr	855	;----------------------------
		856	; trim any data not in window
1159	hidnplayr	857
1533	hidnplayr	858	DEBUGF 1,"Trimming window\n"
		859
1514	hidnplayr	860	mov eax, [ebx + TCP_SOCKET.RCV_NXT]
		861	sub eax, [edx + TCP_segment.SequenceNumber]
1318	hidnplayr	862
1514	hidnplayr	863	test eax, eax
1533	hidnplayr	864	jz .no_duplicate
1274	hidnplayr	865
1514	hidnplayr	866	test [edx + TCP_segment.Flags], TH_SYN
		867	jz .no_drop
		868
		869	and [edx + TCP_segment.Flags], not (TH_SYN)
		870	inc [edx + TCP_segment.SequenceNumber]
		871
		872	cmp [edx + TCP_segment.UrgentPointer], 1
		873	jl @f
		874
		875	dec [edx + TCP_segment.UrgentPointer]
		876
		877	jmp .no_drop
		878	@@:
		879
		880	and [edx + TCP_segment.Flags], not (TH_URG)
		881	dec eax
1533	hidnplayr	882	jz .no_duplicate
1514	hidnplayr	883	.no_drop:
		884
1533	hidnplayr	885	DEBUGF 1,"Going to drop %u out of %u bytes\n", eax, ecx
1529	hidnplayr	886
1514	hidnplayr	887	; eax holds number of bytes to drop
		888
		889	;----------------------------------
		890	; Check for entire duplicate packet
		891
		892	cmp eax, ecx
		893	jge .duplicate
		894
		895	;;; TODO: figure 28.30
		896
		897	;------------------------
		898	; Check for duplicate FIN
		899
		900	test [edx + TCP_segment.Flags], TH_FIN
		901	jz @f
		902	inc ecx
		903	cmp eax, ecx
		904	dec ecx
		905	jne @f
		906
		907	mov eax, ecx
		908	and [edx + TCP_segment.Flags], not TH_FIN
1529	hidnplayr	909	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1514	hidnplayr	910	jmp .no_duplicate
		911	@@:
		912
		913	; Handle the case when a bound socket connects to itself
		914	; Allow packets with a SYN and an ACKto continue with the processing
		915
		916	;-------------------------------------
		917	; Generate duplicate ACK if nescessary
		918
		919	; This code also handles simultaneous half-open or self-connects
		920
		921	test eax, eax
		922	jnz .drop_after_ack
		923
		924	cmp [edx + TCP_segment.Flags], TH_ACK
		925	jz .drop_after_ack
		926
		927	.duplicate:
		928
1533	hidnplayr	929	DEBUGF 1,"Duplicate received\n"
1529	hidnplayr	930
1514	hidnplayr	931	;----------------------------------------
		932	; Update statistics for duplicate packets
		933
		934	;;; TODO
		935
1529	hidnplayr	936	jmp .drop ;;; DROP the packet ??
1514	hidnplayr	937
		938	.no_duplicate:
		939
		940	;-----------------------------------------------
		941	; Remove duplicate data and update urgent offset
		942
		943	add [edx + TCP_segment.SequenceNumber], eax
		944
		945	;;; TODO
		946
		947	sub [edx + TCP_segment.UrgentPointer], ax
		948	jg @f
		949
		950	and [edx + TCP_segment.Flags], not (TH_URG)
		951	mov [edx + TCP_segment.UrgentPointer], 0
		952	@@:
		953
		954	;--------------------------------------------------
		955	; Handle data that arrives after process terminates
		956
		957	cmp [ebx + SOCKET.PID], 0
1533	hidnplayr	958	jg @f
1514	hidnplayr	959
		960	cmp [ebx + TCP_SOCKET.t_state], TCB_CLOSE_WAIT
		961	jle @f
		962
		963	test ecx, ecx
		964	jz @f
		965
		966	;;; Close the socket
		967	;;; update stats
		968
		969	jmp .drop_with_reset
		970	@@:
		971
		972	;----------------------------------------
		973	; Remove data beyond right edge of window
		974
		975	mov eax, [edx + TCP_segment.SequenceNumber]
		976	add eax, ecx
		977	sub eax, [ebx + TCP_SOCKET.RCV_NXT]
		978	sub ax, [ebx + TCP_SOCKET.RCV_WND]
		979
		980	; eax now holds the number of bytes to drop
		981
		982	jle .no_excess_data
		983
		984	;;; TODO: update stats
		985
		986	cmp eax, ecx
		987	jl .dont_drop_all
		988
		989	;;; TODO 700-736
		990
		991	.dont_drop_all:
		992
		993	.no_excess_data:
		994
		995	;-----------------
		996	; Record timestamp
		997
		998	;;; TODO 737-746
		999
		1000	;------------------
		1001	; Process RST flags
		1002
		1003	test [edx + TCP_segment.Flags], TH_RST
		1004	jz .rst_skip
		1005
1529	hidnplayr	1006	DEBUGF 1,"Got an RST flag"
		1007
1514	hidnplayr	1008	mov eax, [ebx + TCP_SOCKET.t_state]
		1009	shl eax, 2
		1010	jmp dword [eax + .rst_sw_list]
		1011
		1012	.rst_sw_list:
		1013	dd .rst_skip ;TCB_CLOSED
		1014	dd .rst_skip ;TCB_LISTEN
		1015	dd .rst_skip ;TCB_SYN_SENT
		1016	dd .econnrefused ;TCB_SYN_RECEIVED
		1017	dd .econnreset ;TCB_ESTABLISHED
		1018	dd .econnreset ;TCB_CLOSE_WAIT
		1019	dd .econnreset ;TCB_FIN_WAIT_1
		1020	dd .rst_close ;TCB_CLOSING
		1021	dd .rst_close ;TCB_LAST_ACK
		1022	dd .econnreset ;TCB_FIN_WAIT_2
		1023	dd .rst_close ;TCB_TIMED_WAIT
		1024
		1025	.econnrefused:
		1026
1529	hidnplayr	1027	DEBUGF 1,"Connection refused"
		1028
1514	hidnplayr	1029	;;; TODO: debug info
		1030
		1031	jmp .close
		1032
		1033	.econnreset:
		1034
1529	hidnplayr	1035	DEBUGF 1,"Connection reset"
		1036
1514	hidnplayr	1037	;;; TODO: debug info
1529	hidnplayr	1038	.close:
1514	hidnplayr	1039
1529	hidnplayr	1040	DEBUGF 1,"Closing connection"
		1041
1514	hidnplayr	1042	;;; update stats
		1043
		1044	.rst_close:
		1045
1529	hidnplayr	1046	DEBUGF 1,"Closing with reset"
		1047
1514	hidnplayr	1048	;;; Close the socket
		1049	jmp .drop
		1050
		1051	.rst_skip:
		1052
		1053	;--------------------------------------
		1054	; handle SYN-full and ACK-less segments
		1055
		1056	test [edx + TCP_segment.Flags], TH_SYN
		1057	jz @f
		1058
		1059	;;; tcp_drop ( ECONNRESET)
		1060	jmp .drop_with_reset
		1061
		1062	test [edx + TCP_segment.Flags], TH_ACK
		1063	jz .drop
		1064
		1065	;----------------
		1066	; Process the ACK
		1067
		1068	cmp [ebx + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		1069	jg .ack_dup
		1070	jl .ack_nodup
		1071
1533	hidnplayr	1072	DEBUGF 1,"TCP state = syn received"
		1073
1514	hidnplayr	1074	;;;;;
		1075
		1076	.ack_dup:
		1077
1533	hidnplayr	1078	DEBUGF 1,"Duplicate ACK"
		1079
1514	hidnplayr	1080	;;;;
		1081
		1082	.ack_nodup:
		1083
		1084	;;;; 887
		1085
1533	hidnplayr	1086	DEBUGF 1,"New ACK"
		1087
1514	hidnplayr	1088	;-------------------------------------------------
1519	hidnplayr	1089	; If the congestion window was inflated to account
1514	hidnplayr	1090	; for the other side's cached packets, retrace it
		1091
		1092	;;;; 888 - 902
		1093
		1094
		1095	;------------------------------------------
		1096	; RTT measurements and retransmission timer
		1097
		1098	;;;;; 903 - 926
		1099
1519	hidnplayr	1100	mov [ebx + TCP_SOCKET.timer_retransmission], 0
1514	hidnplayr	1101
1519	hidnplayr	1102	mov eax, [ebx + TCP_SOCKET.SND_MAX]
		1103	cmp eax, [edx + TCP_segment.AckNumber]
		1104	je .all_outstanding
		1105	mov [ebx + TCP_SOCKET.timer_retransmission], 120 ;;;; TODO: correct this value
		1106	.all_outstanding:
		1107
1514	hidnplayr	1108	;-------------------------------------------
		1109	; Open congestion window in response to ACKs
		1110
		1111	;;;;
		1112
		1113
		1114	;------------------------------------------
		1115	; Remove acknowledged data from send buffer
		1116
1533	hidnplayr	1117	xor ecx, ecx ;;;;;;
		1118	lea eax, [ebx + STREAM_SOCKET.snd]
		1119	call SOCKET_ring_free ;;;; 943 - 956
1514	hidnplayr	1120
		1121	;---------------------------------------
		1122	; Wake up process waiting on send buffer
		1123
1529	hidnplayr	1124	mov eax, ebx
		1125	call SOCKET_notify_owner
1514	hidnplayr	1126
		1127	mov eax, [ebx + TCP_SOCKET.t_state]
		1128	shl eax, 2
		1129	jmp dword [eax + .ACK_sw_list]
		1130
		1131	.ACK_sw_list:
		1132	dd .step6 ;TCB_CLOSED
		1133	dd .step6 ;TCB_LISTEN
		1134	dd .step6 ;TCB_SYN_SENT
		1135	dd .step6 ;TCB_SYN_RECEIVED
		1136	dd .step6 ;TCB_ESTABLISHED
		1137	dd .step6 ;TCB_CLOSE_WAIT
		1138	dd ._963 ;TCB_FIN_WAIT_1
		1139	dd ._958 ;TCB_CLOSING
		1140	dd ._999 ;TCB_LAST_ACK
		1141	dd .step6 ;TCB_FIN_WAIT_2
		1142	dd ._1010 ;TCB_TIMED_WAIT
		1143
		1144
		1145	._963:
		1146
		1147
		1148	jmp .step6
		1149
		1150
		1151	._958:
		1152
		1153	jmp .step6
		1154
		1155	._999:
		1156
		1157	jmp .step6
		1158
		1159
		1160	._1010:
		1161
		1162	jmp .step6
		1163
		1164
		1165
		1166	align 4
		1167	.step6:
		1168
		1169	DEBUGF 1,"step 6\n"
		1170
		1171	;--------------------------
		1172	; update window information
		1173
		1174	test [edx + TCP_segment.Flags], TH_ACK
		1175	jz .no_window_update
		1176
		1177	mov eax, [ebx + TCP_SOCKET.SND_WL1]
		1178	cmp eax, [edx + TCP_segment.SequenceNumber]
		1179
		1180	;;;; 1021
		1181
		1182	;----------------------------------
		1183	; Keep track of pure window updates
		1184
		1185	test ecx, ecx
		1186	jz @f
		1187
		1188	mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1189	cmp eax, [edx + TCP_segment.AckNumber]
		1190	jne @f
		1191
		1192	;; mov eax, tiwin
		1193	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		1194	jle @f
		1195
		1196	;;; update stats
		1197
		1198	@@:
		1199
		1200	;; mov eax, incoming window
		1201	cmp eax, [ebx + TCP_SOCKET.max_sndwnd]
		1202	jle @f
		1203	mov [ebx + TCP_SOCKET.max_sndwnd], eax
		1204	@@:
		1205	mov [ebx + TCP_SOCKET.SND_WND], eax
		1206
		1207	mov eax, [edx + TCP_segment.SequenceNumber]
		1208	mov [ebx + TCP_SOCKET.SND_WL1], eax
		1209
		1210	mov eax, [edx + TCP_segment.AckNumber]
		1211	mov [ebx + TCP_SOCKET.SND_WL2], eax
		1212
		1213	;;; needoutput = 1
		1214
		1215	.no_window_update:
		1216
		1217	;-----------------
		1218	; process URG flag
		1219
		1220	test [edx + TCP_segment.Flags], TH_URG
		1221	jz .not_urgent
		1222
		1223	cmp [edx + TCP_segment.UrgentPointer], 0
		1224	jz .not_urgent
		1225
		1226	cmp [ebx + TCP_SOCKET.t_state], TCB_TIMED_WAIT
		1227	je .not_urgent
		1228
		1229	; Ignore bogus urgent offsets
		1230
		1231	;;; 1040-1050
		1232
		1233	movzx eax, [edx + TCP_segment.UrgentPointer]
1533	hidnplayr	1234	add eax, [ebx + STREAM_SOCKET.rcv + RING_BUFFER.size]
1514	hidnplayr	1235	cmp eax, SOCKET_MAXDATA
		1236	jle .not_urgent
		1237
		1238	mov [edx + TCP_segment.UrgentPointer], 0
		1239	and [edx + TCP_segment.Flags], not (TH_URG)
		1240	jmp .do_data
		1241
		1242	.not_urgent:
		1243
		1244	;--------------------------------------
		1245	; processing of received urgent pointer
		1246
1529	hidnplayr	1247	;;; TODO (1051-1093)
1514	hidnplayr	1248
1529	hidnplayr	1249	;--------------------------------
		1250	; process the data in the segment
1514	hidnplayr	1251
1529	hidnplayr	1252	.do_data:
1514	hidnplayr	1253
1533	hidnplayr	1254	DEBUGF 1,"TCP: do data\n"
1514	hidnplayr	1255
		1256	test [edx + TCP_segment.Flags], TH_FIN
1529	hidnplayr	1257	jnz .process_fin
1514	hidnplayr	1258
1533	hidnplayr	1259	cmp [ebx + TCP_SOCKET.t_state], TCB_FIN_WAIT_1
1514	hidnplayr	1260	jge .dont_do_data
		1261
1533	hidnplayr	1262	test ecx, ecx
		1263	jz .final_processing
		1264
1514	hidnplayr	1265	DEBUGF 1,"Processing data in segment\n"
		1266
1533	hidnplayr	1267	;; TODO: check if data is in sequence !
1514	hidnplayr	1268
1533	hidnplayr	1269	movzx eax, [edx + TCP_segment.DataOffset] ;;; todo: remember this in.. edi ?
		1270	and eax, 0xf0
		1271	shr al, 2
		1272
		1273	lea esi, [edx + eax]
		1274
		1275	or [ebx + TCP_SOCKET.t_flags], TF_DELACK
		1276	add [ebx + TCP_SOCKET.RCV_NXT], ecx ;;; right ?
		1277
		1278	lea eax, [ebx + STREAM_SOCKET.rcv]
		1279	call SOCKET_ring_write
		1280
		1281	mov eax, ebx
		1282	call SOCKET_notify_owner
		1283
1514	hidnplayr	1284	jmp .final_processing
		1285
		1286
		1287	.dont_do_data:
		1288
		1289	;---------------
		1290	; FIN processing
		1291
		1292	.process_fin:
		1293
		1294	DEBUGF 1,"Processing FIN\n"
		1295
		1296	mov eax, [ebx + TCP_SOCKET.t_state]
		1297	shl eax, 2
		1298	jmp dword [eax + .FIN_sw_list]
		1299
		1300	.FIN_sw_list:
		1301	dd .no_fin ;TCB_CLOSED
		1302	dd .no_fin ;TCB_LISTEN
		1303	dd .no_fin ;TCB_SYN_SENT
1533	hidnplayr	1304	dd .fin_syn_est ;TCB_SYN_RECEIVED
		1305	dd .fin_syn_est ;TCB_ESTABLISHED
1514	hidnplayr	1306	dd .no_fin ;TCB_CLOSE_WAIT
1533	hidnplayr	1307	dd .fin_wait1 ;TCB_FIN_WAIT_1
1514	hidnplayr	1308	dd .no_fin ;TCB_CLOSING
		1309	dd .no_fin ;TCB_LAST_ACK
1533	hidnplayr	1310	dd .fin_wait2 ;TCB_FIN_WAIT_2
		1311	dd .fin_timed ;TCB_TIMED_WAIT
1514	hidnplayr	1312
		1313
		1314
1533	hidnplayr	1315	.fin_syn_est:
1514	hidnplayr	1316
1533	hidnplayr	1317	jmp .final_processing
1514	hidnplayr	1318
1533	hidnplayr	1319	.fin_wait1:
1514	hidnplayr	1320
1533	hidnplayr	1321	jmp .final_processing
1514	hidnplayr	1322
1533	hidnplayr	1323	.fin_wait2:
1514	hidnplayr	1324
1533	hidnplayr	1325	jmp .final_processing
		1326
		1327	.fin_timed:
		1328
		1329	jmp .final_processing
		1330
1514	hidnplayr	1331	.no_fin:
		1332
		1333	;-----------------
		1334	; Final processing
		1335
		1336	.final_processing:
		1337
		1338	DEBUGF 1,"Final processing\n"
		1339
1533	hidnplayr	1340	mov [ebx + SOCKET.lock], 0
		1341
1514	hidnplayr	1342	;;; if debug enabled, output packet
		1343
		1344	;test ;;;needoutput = 1
		1345	;jnz .outputnow
		1346
		1347	test [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1529	hidnplayr	1348	jnz .ack_now
1514	hidnplayr	1349
1529	hidnplayr	1350	call kernel_free
		1351	add esp, 4
		1352	ret
		1353
		1354	.ack_now:
		1355
		1356	DEBUGF 1,"ACK now!\n"
		1357
		1358	push ebx
		1359	mov eax, ebx
1514	hidnplayr	1360	call TCP_output
1529	hidnplayr	1361	pop ebx
1514	hidnplayr	1362
1274	hidnplayr	1363	call kernel_free
1529	hidnplayr	1364	add esp, 4
		1365	ret
1274	hidnplayr	1366
1514	hidnplayr	1367	;------------------------------------------
		1368	; Generate an ACK, droping incoming segment
1274	hidnplayr	1369
1514	hidnplayr	1370	align 4
		1371	.drop_after_ack:
1274	hidnplayr	1372
1514	hidnplayr	1373	DEBUGF 1,"Drop after ACK\n"
1274	hidnplayr	1374
1514	hidnplayr	1375	test [edx + TCP_segment.Flags], TH_RST
		1376	jnz .drop
1274	hidnplayr	1377
1514	hidnplayr	1378	and [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1274	hidnplayr	1379
1529	hidnplayr	1380	push ebx
		1381	mov eax, ebx
1514	hidnplayr	1382	call TCP_output
1529	hidnplayr	1383	pop ebx
1318	hidnplayr	1384
1514	hidnplayr	1385	call kernel_free
1529	hidnplayr	1386	add esp, 4
		1387	ret
1274	hidnplayr	1388
1514	hidnplayr	1389
		1390	;-------------------------------------------
		1391	; Generate an RST, dropping incoming segment
		1392
		1393	align 4
		1394	.drop_with_reset:
		1395
		1396	DEBUGF 1,"Drop with reset\n"
		1397
		1398	test [edx + TCP_segment.Flags], TH_RST
		1399	jnz .drop
		1400
		1401	;;; if its a multicast/broadcast, also drop
		1402
		1403	test [edx + TCP_segment.Flags], TH_ACK
		1404	jnz .respond_ack
		1405
		1406	test [edx + TCP_segment.Flags], TH_SYN
		1407	jnz .respond_syn
		1408
		1409	call kernel_free
1529	hidnplayr	1410	add esp, 4
		1411	ret
1514	hidnplayr	1412
		1413	.respond_ack:
		1414
1533	hidnplayr	1415	mov dl, TH_RST
1514	hidnplayr	1416
1533	hidnplayr	1417	push ebx
1529	hidnplayr	1418	call TCP_respond_segment
1533	hidnplayr	1419	pop ebx
1514	hidnplayr	1420
		1421	jmp .destroy_new_socket
		1422
		1423
		1424	.respond_syn:
		1425
1533	hidnplayr	1426	mov dl, TH_RST + TH_ACK
1514	hidnplayr	1427
1533	hidnplayr	1428	push ebx
		1429	call TCP_respond_socket
		1430	pop ebx
1514	hidnplayr	1431
		1432	jmp .destroy_new_socket
		1433
		1434	;-----
		1435	; Drop
		1436
		1437	align 4
		1438	.drop:
		1439
		1440	DEBUGF 1,"Dropping packet\n"
		1441
		1442	;;;; If debugging options are enabled, output the packet somwhere
		1443
		1444	.destroy_new_socket:
		1445
		1446	;;;; kill the newly created socket
		1447
		1448	call kernel_free
1529	hidnplayr	1449	add esp, 4
		1450	ret
1514	hidnplayr	1451
		1452
		1453
		1454
		1455
		1456
		1457	;---------------------------
		1458	;
		1459	; TCP_pull_out_of_band
		1460	;
		1461	; IN: eax =
		1462	; ebx = socket ptr
		1463	; edx = tcp packet ptr
		1464	;
		1465	; OUT: /
		1466	;
		1467	;---------------------------
		1468
		1469	align 4
		1470	TCP_pull_out_of_band:
		1471
		1472	DEBUGF 1,"TCP_pull_out_of_band\n"
		1473
		1474	;;;; 1282-1305
		1475
1318	hidnplayr	1476	ret
		1477
		1478
		1479
		1480	;-----------------------------------------------------------------
		1481	;
1514	hidnplayr	1482	; TCP_output
1318	hidnplayr	1483	;
1519	hidnplayr	1484	; IN: eax = socket pointer
1514	hidnplayr	1485	;; esi = ptr to data
		1486	;; ecx = number of data bytes
		1487	;
1318	hidnplayr	1488	; OUT: /
		1489	;
		1490	;-----------------------------------------------------------------
		1491	align 4
1514	hidnplayr	1492	TCP_output:
1318	hidnplayr	1493
1514	hidnplayr	1494	DEBUGF 1,"TCP_output, socket: %x\n", eax
1318	hidnplayr	1495
1514	hidnplayr	1496	; We'll detect the length of the data to be transmitted, and flags to be used
		1497	; If there is some data, or any critical controls to send (SYN / RST), then transmit
		1498	; Otherwise, investigate further
1318	hidnplayr	1499
1514	hidnplayr	1500	mov ebx, [eax + TCP_SOCKET.SND_MAX]
		1501	cmp ebx, [eax + TCP_SOCKET.SND_UNA]
		1502	jne .not_idle
1318	hidnplayr	1503
1514	hidnplayr	1504	mov ebx, [eax + TCP_SOCKET.t_idle]
		1505	cmp ebx, [eax + TCP_SOCKET.t_rxtcur]
		1506	jle .not_idle
1318	hidnplayr	1507
1514	hidnplayr	1508	; We have been idle for a while and no ACKS are expected to clock out any data we send..
		1509	; Slow start to get ack "clock" running again.
1318	hidnplayr	1510
1514	hidnplayr	1511	mov ebx, [eax + TCP_SOCKET.t_maxseg]
		1512	mov [eax + TCP_SOCKET.SND_CWND], ebx
1318	hidnplayr	1513
1514	hidnplayr	1514	.not_idle:
		1515	.again:
		1516	mov ebx, [eax + TCP_SOCKET.SND_NXT] ; calculate offset
		1517	sub ebx, [eax + TCP_SOCKET.SND_UNA] ;
1318	hidnplayr	1518
1514	hidnplayr	1519	mov ecx, [eax + TCP_SOCKET.SND_WND] ; determine window
		1520	cmp ecx, [eax + TCP_SOCKET.SND_CWND] ;
		1521	jl @f ;
		1522	mov ecx, [eax + TCP_SOCKET.SND_CWND] ;
		1523	@@: ;
1318	hidnplayr	1524
1529	hidnplayr	1525	call TCP_outflags ; in dl
1318	hidnplayr	1526
1514	hidnplayr	1527	; If in persist timeout with window of 0, send 1 byte.
		1528	; Otherwise, if window is small but nonzero, and timer expired,
		1529	; we will send what we can and go to transmit state
1318	hidnplayr	1530
1514	hidnplayr	1531	test [eax + TCP_SOCKET.t_force], -1
		1532	jz .no_persist_timeout
1318	hidnplayr	1533
1514	hidnplayr	1534	test ecx, ecx
		1535	jnz .no_zero_window
1255	hidnplayr	1536
1533	hidnplayr	1537	cmp ebx, [eax + STREAM_SOCKET.snd + RING_BUFFER.size]
1514	hidnplayr	1538	jge @f
1255	hidnplayr	1539
1514	hidnplayr	1540	and dl, not (TH_FIN) ; clear the FIN flag ??? how can it be set before?
1255	hidnplayr	1541
1514	hidnplayr	1542	@@:
		1543	inc ecx
		1544	jmp .no_persist_timeout
1255	hidnplayr	1545
1514	hidnplayr	1546	.no_zero_window:
1254	hidnplayr	1547
1529	hidnplayr	1548	mov [eax + TCP_SOCKET.timer_persist], 0 ;;;;
1514	hidnplayr	1549	mov [eax + TCP_SOCKET.t_rxtshift], 0
1254	hidnplayr	1550
1514	hidnplayr	1551	.no_persist_timeout:
1159	hidnplayr	1552
1514	hidnplayr	1553	;;;106
1159	hidnplayr	1554
1533	hidnplayr	1555	mov esi, [eax + STREAM_SOCKET.snd + RING_BUFFER.size]
1514	hidnplayr	1556	cmp esi, ecx
		1557	jl @f
		1558	mov esi, ecx
		1559	@@:
		1560	sub esi, ebx
1254	hidnplayr	1561
1514	hidnplayr	1562	cmp esi, -1
		1563	jne .not_minus_one
1159	hidnplayr	1564
1514	hidnplayr	1565	; If FIN has been set, but not ACKed, and we havent been called to retransmit,
		1566	; len (esi) will be -1
		1567	; Otherwise, window shrank after we sent into it.
		1568	; If window shrank to 0, cancel pending retransmit and pull SND_NXT back to (closed) window
		1569	; We will enter persist state below.
		1570	; If window didn't close completely, just wait for an ACK
1159	hidnplayr	1571
1514	hidnplayr	1572	xor esi, esi
1159	hidnplayr	1573
1514	hidnplayr	1574	test ecx, ecx
		1575	jnz @f
1159	hidnplayr	1576
1529	hidnplayr	1577	mov [eax + TCP_SOCKET.timer_retransmission], 0 ; cancel retransmit
1274	hidnplayr	1578
1514	hidnplayr	1579	push [eax + TCP_SOCKET.SND_UNA]
		1580	pop [eax + TCP_SOCKET.SND_NXT]
		1581	@@:
1254	hidnplayr	1582
1514	hidnplayr	1583	.not_minus_one:
1254	hidnplayr	1584
1514	hidnplayr	1585	;;; 124
1159	hidnplayr	1586
1514	hidnplayr	1587	cmp esi, [eax + TCP_SOCKET.t_maxseg]
		1588	jle @f
1274	hidnplayr	1589
1514	hidnplayr	1590	mov esi, [eax + TCP_SOCKET.t_maxseg]
		1591	;sendalot = 1
1274	hidnplayr	1592
1514	hidnplayr	1593	@@:
1274	hidnplayr	1594
1514	hidnplayr	1595	;;; 128
1274	hidnplayr	1596
1514	hidnplayr	1597	mov edi, [eax + TCP_SOCKET.SND_NXT]
		1598	add edi, esi ; len
		1599	sub edi, [eax + TCP_SOCKET.SND_UNA]
1533	hidnplayr	1600	add edi, [eax + STREAM_SOCKET.snd + RING_BUFFER.size]
1514	hidnplayr	1601	cmp edi, 0
		1602	jle @f
1274	hidnplayr	1603
1514	hidnplayr	1604	and dl, not (TH_FIN) ; clear the FIN flag
1159	hidnplayr	1605
1514	hidnplayr	1606	@@:
1159	hidnplayr	1607
		1608
1529	hidnplayr	1609	; set ecx to space available in receive buffer
		1610	; From now on, ecx will be the window we advertise to the other end
1159	hidnplayr	1611
1529	hidnplayr	1612	mov ecx, SOCKET_MAXDATA
1533	hidnplayr	1613	sub ecx, [eax + STREAM_SOCKET.rcv + RING_BUFFER.size]
1159	hidnplayr	1614
1514	hidnplayr	1615	;------------------------------
		1616	; Sender silly window avoidance
1159	hidnplayr	1617
1529	hidnplayr	1618	cmp ecx, [eax + TCP_SOCKET.t_maxseg]
1514	hidnplayr	1619	je .send
1274	hidnplayr	1620
1514	hidnplayr	1621	;;; TODO: 144-145
1274	hidnplayr	1622
1514	hidnplayr	1623	test [eax + TCP_SOCKET.t_force], -1
		1624	jnz .send
1274	hidnplayr	1625
1529	hidnplayr	1626	mov ebx, [eax + TCP_SOCKET.max_sndwnd]
		1627	shr ebx, 1
		1628	cmp ecx, ebx
		1629	jge .send
1274	hidnplayr	1630
1529	hidnplayr	1631	mov ebx, [eax + TCP_SOCKET.SND_NXT]
		1632	cmp ebx, [eax + TCP_SOCKET.SND_MAX]
		1633	jl .send
1254	hidnplayr	1634
1514	hidnplayr	1635	;----------------------------------------
		1636	; Check if a window update should be sent
1159	hidnplayr	1637
1529	hidnplayr	1638	test ecx, ecx ; window
		1639	jz .no_window
1159	hidnplayr	1640
1514	hidnplayr	1641	;;; TODO 154-172
1159	hidnplayr	1642
1514	hidnplayr	1643	.no_window:
1159	hidnplayr	1644
1514	hidnplayr	1645	;--------------------------
		1646	; Should a segment be sent?
1159	hidnplayr	1647
1514	hidnplayr	1648	test [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
		1649	jnz .send
1159	hidnplayr	1650
1514	hidnplayr	1651	test dl, TH_SYN + TH_RST
		1652	jnz .send
1159	hidnplayr	1653
1514	hidnplayr	1654	mov eax, [ebx + TCP_SOCKET.SND_UP]
		1655	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
		1656	jg .send
1249	hidnplayr	1657
1514	hidnplayr	1658	test dl, TH_FIN
		1659	jz .enter_persist
1318	hidnplayr	1660
1514	hidnplayr	1661	test [ebx + TCP_SOCKET.t_flags], TF_SENTFIN
		1662	jnz .send
1254	hidnplayr	1663
1514	hidnplayr	1664	mov eax, [ebx + TCP_SOCKET.SND_NXT]
		1665	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
		1666	je .send
1254	hidnplayr	1667
1514	hidnplayr	1668	;--------------------
		1669	; Enter persist state
1318	hidnplayr	1670
1514	hidnplayr	1671	.enter_persist:
1318	hidnplayr	1672
1519	hidnplayr	1673	DEBUGF 1,"Entering persist state\n"
1318	hidnplayr	1674
1514	hidnplayr	1675	;--------------------------------------
		1676	; No reason to send a segment, just ret
1318	hidnplayr	1677
1514	hidnplayr	1678	DEBUGF 1,"No reason to send a segment\n"
1318	hidnplayr	1679
1514	hidnplayr	1680	ret
1318	hidnplayr	1681
		1682
1514	hidnplayr	1683	;-----------------------------------------------
		1684	;
		1685	; Send a segment
		1686	;
1529	hidnplayr	1687	; eax = socket pointer
1514	hidnplayr	1688	; dl = flags
		1689	;
		1690	;-----------------------------------------------
1318	hidnplayr	1691
1529	hidnplayr	1692	.send:
1318	hidnplayr	1693
1514	hidnplayr	1694	DEBUGF 1,"Preparing to send a segment\n"
1318	hidnplayr	1695
1529	hidnplayr	1696	mov edi, TCP_segment.Data ; edi will contain headersize
1318	hidnplayr	1697
1529	hidnplayr	1698	sub esp, 8 ; create some space on stack
		1699	push eax ; save this too..
		1700
1514	hidnplayr	1701	;------------------------------------
		1702	; Send options with first SYN segment
1318	hidnplayr	1703
1514	hidnplayr	1704	test dl, TH_SYN
		1705	jz .no_options
1318	hidnplayr	1706
1529	hidnplayr	1707	push [eax + TCP_SOCKET.ISS]
		1708	pop [eax + TCP_SOCKET.SND_NXT]
1318	hidnplayr	1709
1529	hidnplayr	1710	test [eax + TCP_SOCKET.t_flags], TF_NOOPT
1514	hidnplayr	1711	jnz .no_options
1318	hidnplayr	1712
1529	hidnplayr	1713	mov ecx, 1460
		1714	or ecx, TCP_OPT_MAXSEG shl 24 + 4 shl 16
		1715	bswap ecx
		1716	push ecx
		1717	add di, 4
1514	hidnplayr	1718
1529	hidnplayr	1719	test [eax + TCP_SOCKET.t_flags], TF_REQ_SCALE
1514	hidnplayr	1720	jz .no_syn
		1721
		1722	test dl, TH_ACK
		1723	jnz .scale_opt
		1724
1529	hidnplayr	1725	test [eax + TCP_SOCKET.t_flags], TF_RCVD_SCALE
1514	hidnplayr	1726	jz .no_syn
		1727
		1728	.scale_opt:
1529	hidnplayr	1729	movzx ecx, byte [eax + TCP_SOCKET.request_r_scale]
		1730	or ecx, TCP_OPT_WINDOW shl 24 + 4 shl 16 + TCP_OPT_NOP shl 8
		1731	bswap ecx
		1732	pushd ecx
1514	hidnplayr	1733	add di, 4
1159	hidnplayr	1734
1514	hidnplayr	1735	.no_syn:
1159	hidnplayr	1736
1514	hidnplayr	1737	;------------------------------------
		1738	; Make the timestamp option if needed
1159	hidnplayr	1739
1529	hidnplayr	1740	test [eax + TCP_SOCKET.t_flags], TF_REQ_TSTMP
1514	hidnplayr	1741	jz .no_timestamp
1159	hidnplayr	1742
1514	hidnplayr	1743	test dl, TH_RST
		1744	jnz .no_timestamp
		1745
		1746	test dl, TH_ACK
		1747	jz .timestamp
		1748
1529	hidnplayr	1749	test [eax + TCP_SOCKET.t_flags], TF_RCVD_TSTMP
1514	hidnplayr	1750	jz .no_timestamp
		1751
		1752	.timestamp:
1529	hidnplayr	1753	mov esi, [timer_ticks]
		1754	bswap esi
		1755	push esi
1514	hidnplayr	1756	pushw 0
1529	hidnplayr	1757	pushd TCP_OPT_TIMESTAMP + 10 shl 8 + TCP_OPT_NOP shl 16 + TCP_OPT_NOP shl 24
1514	hidnplayr	1758	add di, 10
		1759
		1760	.no_timestamp:
		1761	;; TODO: check if we dont exceed the max segment size
		1762
		1763	.no_options:
1529	hidnplayr	1764	; eax = socket ptr
		1765	; edx = flags
		1766	; ecx = data size
		1767	; edi = header size
		1768	; esi = snd ring buff ptr
1514	hidnplayr	1769
1533	hidnplayr	1770	mov ecx, [eax + STREAM_SOCKET.snd + RING_BUFFER.size]
		1771	cmp ecx, [eax + TCP_SOCKET.t_maxseg] ;;; right?
		1772	jle @f
		1773	mov ecx, [eax + TCP_SOCKET.t_maxseg]
		1774	@@:
1514	hidnplayr	1775	add ecx, edi ; total TCP segment size
		1776
1529	hidnplayr	1777	; Start by pushing all TCP header values in reverse order on stack
		1778	; (essentially, creating the tcp header!)
1514	hidnplayr	1779
1529	hidnplayr	1780	pushw 0 ; .UrgentPointer dw ?
		1781	pushw 0 ; .Checksum dw ?
		1782	pushw 0x00a0 ; .Window dw ? ;;;;;;;
		1783	shl edi, 2 ; .DataOffset db ? only 4 left-most bits
		1784	shl dx, 8
		1785	or dx, di ; .Flags db ?
		1786	pushw dx
		1787	shr edi, 2 ; .DataOffset db ? ;;;;
1514	hidnplayr	1788
1529	hidnplayr	1789	push [eax + TCP_SOCKET.RCV_NXT] ; .AckNumber dd ?
		1790	ntohld [esp]
1159	hidnplayr	1791
1529	hidnplayr	1792	push [eax + TCP_SOCKET.SND_NXT] ; .SequenceNumber dd ?
		1793	ntohld [esp]
1159	hidnplayr	1794
1529	hidnplayr	1795	push [eax + TCP_SOCKET.RemotePort] ; .DestinationPort dw ?
		1796	ntohlw [esp]
1249	hidnplayr	1797
1529	hidnplayr	1798	push [eax + TCP_SOCKET.LocalPort] ; .SourcePort dw ?
		1799	ntohlw [esp]
1274	hidnplayr	1800
1533	hidnplayr	1801	push edi ; header size
1274	hidnplayr	1802
1529	hidnplayr	1803	; Create the IP packet
		1804	mov ebx, [eax + IP_SOCKET.LocalIP] ; source ip
		1805	mov eax, [eax + IP_SOCKET.RemoteIP] ; dest ip
		1806	mov di, IP_PROTO_TCP shl 8 + 128
		1807	call IPv4_output
		1808	jz .fail
1274	hidnplayr	1809
1529	hidnplayr	1810	;-----------------------------------------
		1811	; Move TCP header from stack to TCP packet
1274	hidnplayr	1812
1533	hidnplayr	1813	push ecx
		1814	mov ecx, [esp+4]
		1815	lea esi, [esp+4+4]
1529	hidnplayr	1816	shr ecx, 2
		1817	rep movsd
1533	hidnplayr	1818	pop ecx ; full TCP packet size
1274	hidnplayr	1819
1533	hidnplayr	1820	pop esi ; headersize
		1821	add esp, esi
1254	hidnplayr	1822
1533	hidnplayr	1823	mov [esp + 4], eax ; packet ptr
1530	hidnplayr	1824	mov [esp + 4+4], edx ; packet size
1254	hidnplayr	1825
1533	hidnplayr	1826	mov edx, edi ; begin of data
		1827	sub edx, esi ; begin of packet (edi = begin of data)
		1828	push ecx
		1829	sub ecx, esi ; data size
1159	hidnplayr	1830
1514	hidnplayr	1831	;--------------
		1832	; Copy the data
1159	hidnplayr	1833
1529	hidnplayr	1834	; eax = ptr to ring struct
		1835	; ecx = buffer size
		1836	; edi = ptr to buffer
1249	hidnplayr	1837
1533	hidnplayr	1838	mov eax, [esp+4] ; socket ptr
		1839	push edx
		1840	add eax, STREAM_SOCKET.snd
1529	hidnplayr	1841	call SOCKET_ring_read
		1842	pop esi ecx
		1843	pop eax
1254	hidnplayr	1844
1533	hidnplayr	1845	test [esi + TCP_segment.Flags], TH_SYN + TH_FIN
		1846	jz @f
		1847	inc [eax + TCP_SOCKET.SND_NXT]
		1848	;;; TODO: update sentfin flag
		1849	@@:
1254	hidnplayr	1850
1533	hidnplayr	1851	;; add [eax + TCP_SOCKET.SND_NXT], ecx
		1852
		1853	mov edx, [eax + TCP_SOCKET.SND_NXT]
		1854	cmp edx, [eax + TCP_SOCKET.SND_MAX]
		1855	jle @f
		1856	mov [eax + TCP_SOCKET.SND_MAX], edx
		1857
		1858	;;;; TODO: time transmission (420)
		1859	@@:
		1860
		1861	;;; TODO: set retransmission timer
		1862
		1863	;--------------------
		1864	; Create the checksum
		1865
1529	hidnplayr	1866	DEBUGF 1,"checksum: ptr=%x size=%u\n", esi, ecx
1159	hidnplayr	1867
1529	hidnplayr	1868	TCP_checksum (eax + IP_SOCKET.LocalIP), (eax + IP_SOCKET.RemoteIP)
		1869	mov [esi+TCP_segment.Checksum], dx
		1870
1514	hidnplayr	1871	;----------------
		1872	; Send the packet
1159	hidnplayr	1873
1529	hidnplayr	1874	DEBUGF 1,"Sending TCP Packet to device %x\n", ebx
		1875	call [ebx + NET_DEVICE.transmit]
		1876	ret
1159	hidnplayr	1877
1514	hidnplayr	1878
1529	hidnplayr	1879	.fail:
		1880	pop ecx
		1881	add esp, ecx
		1882	add esp, 4+4+8+4
		1883	DEBUGF 1,"TCP_output: failed\n"
1159	hidnplayr	1884	ret
		1885
1529	hidnplayr	1886
		1887
1514	hidnplayr	1888	;-------------------------
		1889	;
		1890	; TCP_outflags
		1891	;
		1892	; IN: eax = socket ptr
		1893	;
		1894	; OUT: edx = flags
		1895	;
		1896	;-------------------------
1249	hidnplayr	1897	align 4
1514	hidnplayr	1898	TCP_outflags:
1254	hidnplayr	1899
1514	hidnplayr	1900	mov edx, [eax + TCP_SOCKET.t_state]
		1901	movzx edx, byte [edx + .flaglist]
1254	hidnplayr	1902
1514	hidnplayr	1903	DEBUGF 1,"TCP_outflags, socket: %x, flags: %x\n", eax, dl
		1904
1159	hidnplayr	1905	ret
		1906
1514	hidnplayr	1907	.flaglist:
1159	hidnplayr	1908
1514	hidnplayr	1909	db TH_RST + TH_ACK ; TCB_CLOSED
		1910	db 0 ; TCB_LISTEN
		1911	db TH_SYN ; TCB_SYN_SENT
		1912	db TH_SYN + TH_ACK ; TCB_SYN_RECEIVED
		1913	db TH_ACK ; TCB_ESTABLISHED
		1914	db TH_ACK ; TCB_CLOSE_WAIT
		1915	db TH_SYN + TH_ACK ; TCB_FIN_WAIT_1
		1916	db TH_SYN + TH_ACK ; TCB_CLOSING
		1917	db TH_SYN + TH_ACK ; TCB_LAST_ACK
		1918	db TH_ACK ; TCB_FIN_WAIT_2
		1919	db TH_ACK ; TCB_TIMED_WAIT
1249	hidnplayr	1920
1514	hidnplayr	1921
1529	hidnplayr	1922
		1923
1514	hidnplayr	1924	;-------------------------
		1925	;
		1926	; TCP_drop
		1927	;
		1928	; IN: eax = socket ptr
		1929	;
		1930	; OUT: /
		1931	;
		1932	;-------------------------
1249	hidnplayr	1933	align 4
1514	hidnplayr	1934	TCP_drop:
1254	hidnplayr	1935
1514	hidnplayr	1936	DEBUGF 1,"TCP_drop\n"
1254	hidnplayr	1937
1514	hidnplayr	1938	; cmp [eax + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		1939	; jl .no_syn_received
1159	hidnplayr	1940
1514	hidnplayr	1941	mov [eax + TCP_SOCKET.t_state], TCB_CLOSED
1159	hidnplayr	1942
1514	hidnplayr	1943	call TCP_output
1254	hidnplayr	1944
1514	hidnplayr	1945	; .no_syn_received:
		1946
1159	hidnplayr	1947	ret
		1948
		1949
1254	hidnplayr	1950
		1951
1159	hidnplayr	1952
1514	hidnplayr	1953	;---------------------------------------
		1954	;
1519	hidnplayr	1955	; The easy way to send an ACK/RST/keepalive segment
1514	hidnplayr	1956	;
1529	hidnplayr	1957	; TCP_respond_socket:
		1958	;
		1959	; IN: ebx = socket ptr
1519	hidnplayr	1960	; cl = flags
1514	hidnplayr	1961	;
1529	hidnplayr	1962	;--------------------------------------
1514	hidnplayr	1963	align 4
1529	hidnplayr	1964	TCP_respond_socket:
1254	hidnplayr	1965
1529	hidnplayr	1966	DEBUGF 1,"TCP_respond_socket\n"
1159	hidnplayr	1967
1519	hidnplayr	1968	;---------------------
		1969	; Create the IP packet
		1970
1529	hidnplayr	1971	push cx ebx
		1972	mov eax, [ebx + IP_SOCKET.RemoteIP]
		1973	mov ebx, [ebx + IP_SOCKET.LocalIP]
1519	hidnplayr	1974	mov ecx, TCP_segment.Data
1529	hidnplayr	1975	mov di , IP_PROTO_TCP shl 8 + 128
		1976	call IPv4_output
1519	hidnplayr	1977	test edi, edi
		1978	jz .error
1529	hidnplayr	1979	pop esi cx
		1980	push edx eax
1519	hidnplayr	1981
1529	hidnplayr	1982	;-----------------------------------------------
		1983	; Fill in the TCP header by using the socket ptr
1519	hidnplayr	1984
1529	hidnplayr	1985	mov ax, [esi + TCP_SOCKET.LocalPort]
		1986	rol ax, 8
		1987	stosw
		1988	mov ax, [esi + TCP_SOCKET.RemotePort]
		1989	rol ax, 8
		1990	stosw
		1991	mov eax, [esi + TCP_SOCKET.SND_NXT]
		1992	bswap eax
		1993	stosd
		1994	mov eax, [esi + TCP_SOCKET.RCV_NXT]
		1995	bswap eax
		1996	stosd
		1997	mov al, 0x50 ; Dataoffset: 20 bytes
		1998	stosb
		1999	mov al, cl
		2000	stosb
		2001	mov ax, [esi + TCP_SOCKET.RCV_WND]
		2002	rol ax, 8
		2003	stosw ; window
		2004	xor eax, eax
		2005	stosd ; checksum + urgentpointer
1519	hidnplayr	2006
		2007	;---------------------
		2008	; Fill in the checksum
		2009
		2010	.checksum:
1529	hidnplayr	2011	sub edi, TCP_segment.Data
		2012	mov ecx, TCP_segment.Data
		2013	xchg esi, edi
		2014	TCP_checksum (edi + IP_SOCKET.LocalIP), (esi + IP_SOCKET.RemoteIP)
		2015	mov [esi+TCP_segment.Checksum], dx
1519	hidnplayr	2016
		2017	;--------------------
		2018	; And send the segment
		2019
		2020	call [ebx + NET_DEVICE.transmit]
1159	hidnplayr	2021	ret
		2022
1519	hidnplayr	2023	.error:
1529	hidnplayr	2024	DEBUGF 1,"TCP_respond failed\n"
		2025	add esp, 2+4
1159	hidnplayr	2026
1519	hidnplayr	2027	ret
1514	hidnplayr	2028
1529	hidnplayr	2029
		2030
		2031	;-------------------------
		2032	; TCP_respond.segment:
		2033	;
		2034	; IN: edx = segment ptr (a previously received segment)
		2035	; cl = flags
		2036
		2037	align 4
		2038	TCP_respond_segment:
		2039
		2040	DEBUGF 1,"TCP_respond_segment\n"
		2041
		2042	;---------------------
		2043	; Create the IP packet
		2044
		2045	push cx edx
		2046	mov ebx, [edx - 20 + IPv4_Packet.SourceAddress] ;;;; and what if ip packet had options?!
		2047	mov eax, [edx - 20 + IPv4_Packet.DestinationAddress] ;;;
		2048	mov ecx, TCP_segment.Data
		2049	mov di , IP_PROTO_TCP shl 8 + 128
		2050	call IPv4_output
		2051	jz .error
1533	hidnplayr	2052	pop esi cx
1529	hidnplayr	2053
		2054	push edx eax
		2055
1519	hidnplayr	2056	;---------------------------------------------------
		2057	; Fill in the TCP header by using a received segment
		2058
		2059	mov ax, [esi + TCP_segment.DestinationPort]
		2060	rol ax, 8
		2061	stosw
		2062	mov ax, [esi + TCP_segment.SourcePort]
		2063	rol ax, 8
		2064	stosw
		2065	mov eax, [esi + TCP_segment.AckNumber]
		2066	bswap eax
		2067	stosd
		2068	xor eax, eax
		2069	stosd
		2070	mov al, 0x50 ; Dataoffset: 20 bytes
		2071	stosb
		2072	mov al, cl
		2073	stosb
		2074	mov ax, 1280
		2075	rol ax, 8
		2076	stosw ; window
		2077	xor eax, eax
		2078	stosd ; checksum + urgentpointer
		2079
1529	hidnplayr	2080	;---------------------
		2081	; Fill in the checksum
1519	hidnplayr	2082
1529	hidnplayr	2083	.checksum:
		2084	lea esi, [edi - TCP_segment.Data]
		2085	mov ecx, TCP_segment.Data
		2086	TCP_checksum (esi - 20 + IPv4_Packet.DestinationAddress), (esi - 20 + IPv4_Packet.DestinationAddress)
		2087	mov [esi+TCP_segment.Checksum], dx
1519	hidnplayr	2088
1529	hidnplayr	2089	;--------------------
		2090	; And send the segment
1519	hidnplayr	2091
1529	hidnplayr	2092	call [ebx + NET_DEVICE.transmit]
		2093	ret
1519	hidnplayr	2094
1529	hidnplayr	2095	.error:
		2096	DEBUGF 1,"TCP_respond failed\n"
		2097	add esp, 2+4
1519	hidnplayr	2098
		2099	ret
		2100
		2101
		2102
1254	hidnplayr	2103
		2104	;---------------------------------------------------------------------------
		2105	;
		2106	; TCP_API
		2107	;
		2108	; This function is called by system function 75
		2109	;
		2110	; IN: subfunction number in bl
		2111	; device number in bh
		2112	; ecx, edx, .. depends on subfunction
		2113	;
		2114	; OUT:
		2115	;
		2116	;---------------------------------------------------------------------------
		2117	align 4
		2118	TCP_API:
		2119
		2120	movzx eax, bh
		2121	shl eax, 2
		2122
		2123	test bl, bl
		2124	jz .packets_tx ; 0
		2125	dec bl
		2126	jz .packets_rx ; 1
		2127
		2128	.error:
		2129	mov eax, -1
		2130	ret
		2131
		2132	.packets_tx:
1514	hidnplayr	2133	add eax, TCP_segments_tx
1254	hidnplayr	2134	mov eax, [eax]
		2135	ret
		2136
		2137	.packets_rx:
1514	hidnplayr	2138	add eax, TCP_segments_rx
1254	hidnplayr	2139	mov eax, [eax]
		2140	ret

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(root)/kernel/branches/net/network/tcp.inc – Rev 1533