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: 1543 $
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
1196	hidnplayr	93	align 4
		94	uglobal
1514	hidnplayr	95	TCP_segments_tx rd IP_MAX_INTERFACES
		96	TCP_segments_rx rd IP_MAX_INTERFACES
		97	TCP_bytes_rx rq IP_MAX_INTERFACES
		98	TCP_bytes_tx rq IP_MAX_INTERFACES
		99	TCP_sequence_num dd ?
1196	hidnplayr	100	endg
		101
		102
		103	;-----------------------------------------------------------------
		104	;
		105	; TCP_init
		106	;
		107	; This function resets all TCP variables
		108	;
		109	;-----------------------------------------------------------------
1529	hidnplayr	110	macro TCP_init {
1196	hidnplayr	111
		112	xor eax, eax
1514	hidnplayr	113	mov edi, TCP_segments_tx
		114	mov ecx, (6*IP_MAX_INTERFACES)
1196	hidnplayr	115	rep stosd
		116
1529	hidnplayr	117	pseudo_random eax
		118	mov [TCP_sequence_num], eax
1196	hidnplayr	119
1529	hidnplayr	120	}
1196	hidnplayr	121
		122
1519	hidnplayr	123	;----------------------
1196	hidnplayr	124	;
1159	hidnplayr	125	;
1519	hidnplayr	126	;----------------------
1529	hidnplayr	127	macro TCP_timer_160ms {
1159	hidnplayr	128
1529	hidnplayr	129	local .loop
		130	local .exit
		131
1514	hidnplayr	132	mov eax, net_sockets
		133	.loop:
		134	mov eax, [eax + SOCKET.NextPtr]
		135	or eax, eax
1159	hidnplayr	136	jz .exit
		137
1542	hidnplayr	138	cmp [eax + SOCKET.Protocol], IP_PROTO_TCP ;;; We should also check if family is AF_INET
1514	hidnplayr	139	jne .loop
1249	hidnplayr	140
1519	hidnplayr	141	dec [eax + TCP_SOCKET.timer_ack]
1514	hidnplayr	142	jnz .loop
1159	hidnplayr	143
1519	hidnplayr	144	DEBUGF 1,"TCP ack for socket %x expired, time to piggyback!\n", eax
1159	hidnplayr	145
1519	hidnplayr	146	push eax
1529	hidnplayr	147	call TCP_respond_socket
1514	hidnplayr	148	pop eax
1159	hidnplayr	149
1519	hidnplayr	150	jmp .loop
1159	hidnplayr	151
		152	.exit:
1519	hidnplayr	153
1529	hidnplayr	154	}
1159	hidnplayr	155
		156
1519	hidnplayr	157	;-----------------------------------------------------------------
1159	hidnplayr	158	;
		159	;
1519	hidnplayr	160	;-----------------------------------------------------------------
1529	hidnplayr	161	macro TCP_timer_640ms {
1159	hidnplayr	162
1529	hidnplayr	163	local .loop
		164	local .exit
		165
1519	hidnplayr	166	; Update TCP sequence number
		167
1514	hidnplayr	168	add [TCP_sequence_num], 64000
1159	hidnplayr	169
1519	hidnplayr	170	; scan through all the active TCP sockets, decrementing ALL timers
		171	; timers do not have the chance to wrap because of the keepalive timer will kill the socket when it expires
1159	hidnplayr	172
1519	hidnplayr	173	mov eax, net_sockets
		174	.loop:
		175	mov eax, [eax + SOCKET.NextPtr]
		176	.check_only:
		177	or eax, eax
		178	jz .exit
1159	hidnplayr	179
1542	hidnplayr	180	cmp [eax + SOCKET.Protocol], IP_PROTO_TCP ;;; We should also check if family is AF_INET
1519	hidnplayr	181	jne .loop
1159	hidnplayr	182
1529	hidnplayr	183	inc [eax + TCP_SOCKET.t_idle]
		184	dec [eax + TCP_SOCKET.timer_retransmission]
1519	hidnplayr	185	jnz .check_more2
1254	hidnplayr	186
1519	hidnplayr	187	DEBUGF 1,"socket %x: Retransmission timer expired\n", eax
1159	hidnplayr	188
1519	hidnplayr	189	push eax
		190	call TCP_output
		191	pop eax
1159	hidnplayr	192
1519	hidnplayr	193	.check_more2:
		194	dec [eax + TCP_SOCKET.timer_keepalive]
		195	jnz .check_more3
1159	hidnplayr	196
1519	hidnplayr	197	DEBUGF 1,"socket %x: Keepalive expired\n", eax
1159	hidnplayr	198
1519	hidnplayr	199	;;; TODO: check socket state and handle accordingly
1318	hidnplayr	200
1519	hidnplayr	201	.check_more3:
		202	dec [eax + TCP_SOCKET.timer_timed_wait]
		203	jnz .check_more5
		204
		205	DEBUGF 1,"socket %x: 2MSL timer expired\n", eax
		206
		207	.check_more5:
		208	dec [eax + TCP_SOCKET.timer_persist]
		209	jnz .loop
		210
		211	DEBUGF 1,"socket %x: persist timer expired\n", eax
		212
		213	jmp .loop
		214	.exit:
1529	hidnplayr	215	}
1519	hidnplayr	216
		217
1529	hidnplayr	218
		219
		220	macro TCP_checksum IP1, IP2 {
		221
		222	;-------------
		223	; Pseudoheader
		224
		225	; protocol type
		226	mov edx, IP_PROTO_TCP
		227
		228	; source address
1530	hidnplayr	229	add dl, byte [IP1+1]
		230	adc dh, byte [IP1+0]
		231	adc dl, byte [IP1+3]
		232	adc dh, byte [IP1+2]
1529	hidnplayr	233
		234	; destination address
1530	hidnplayr	235	adc dl, byte [IP2+1]
		236	adc dh, byte [IP2+0]
		237	adc dl, byte [IP2+3]
		238	adc dh, byte [IP2+2]
1529	hidnplayr	239
		240	; size
		241	adc dl, cl
		242	adc dh, ch
		243
		244	;---------------------
		245	; Real header and data
		246
		247	push esi
		248	call checksum_1
		249	call checksum_2
		250	pop esi
		251
		252	} ; returns in dx only
		253
		254
1533	hidnplayr	255	macro TCP_sendseqinit ptr {
1529	hidnplayr	256
1533	hidnplayr	257	push edi ;;;; i dont like this static use of edi
		258	mov edi, [ptr + TCP_SOCKET.ISS]
		259	mov [ptr + TCP_SOCKET.SND_UP], edi
		260	mov [ptr + TCP_SOCKET.SND_MAX], edi
		261	mov [ptr + TCP_SOCKET.SND_NXT], edi
		262	mov [ptr + TCP_SOCKET.SND_UNA], edi
		263	pop edi
		264
		265	}
		266
		267	macro TCP_rcvseqinit ptr {
		268
		269	push edi
		270	mov edi, [ptr + TCP_SOCKET.IRS]
		271	inc edi
		272	mov [ptr + TCP_SOCKET.RCV_NXT], edi
		273	mov [ptr + TCP_SOCKET.RCV_ADV], edi
		274	pop edi
		275
		276	}
		277
		278
		279
1249	hidnplayr	280	;-----------------------------------------------------------------
		281	;
1514	hidnplayr	282	; TCP_input:
1159	hidnplayr	283	;
1514	hidnplayr	284	; IN: [esp] = ptr to buffer
		285	; [esp+4] = buffer size
		286	; ebx = ptr to device struct
		287	; ecx = segment size
		288	; edx = ptr to TCP segment
1196	hidnplayr	289	;
1514	hidnplayr	290	; esi = ipv4 source address
		291	; edi = ipv4 dest address
		292	;
1196	hidnplayr	293	; OUT: /
		294	;
		295	;-----------------------------------------------------------------
1249	hidnplayr	296	align 4
1514	hidnplayr	297	TCP_input:
1159	hidnplayr	298
1529	hidnplayr	299	DEBUGF 1,"TCP_input size=%u\n", ecx
1514	hidnplayr	300	; 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	301
1514	hidnplayr	302	movzx eax, [edx + TCP_segment.DataOffset]
		303	and eax, 0xf0
1529	hidnplayr	304	shr al, 2
1514	hidnplayr	305
1529	hidnplayr	306	DEBUGF 1,"headersize=%u\n", eax
1514	hidnplayr	307
		308	cmp eax, 20
		309	jl .drop
		310
		311	;-------------------------------
		312	; Now, re-calculate the checksum
		313
1529	hidnplayr	314	push eax ecx edx
		315	pushw [edx + TCP_segment.Checksum]
		316	mov [edx + TCP_segment.Checksum], 0
		317	push esi edi
1514	hidnplayr	318	mov esi, edx
1530	hidnplayr	319	TCP_checksum (esp), (esp+4)
1529	hidnplayr	320	pop esi edi ; yes, swap them (we dont need dest addr)
		321	pop cx ; previous checksum
		322	cmp cx, dx
		323	pop edx ecx esi
1514	hidnplayr	324	jnz .drop
		325
		326	DEBUGF 1,"Checksum is correct\n"
		327
1529	hidnplayr	328	sub ecx, esi ; update packet size
		329	jl .drop
1534	hidnplayr	330	DEBUGF 1,"we got %u bytes of data\n", ecx
1529	hidnplayr	331
1514	hidnplayr	332	;-----------------------------------------------------------------------------------------
		333	; Check if this packet has a timestamp option (We do it here so we can process it quickly)
		334
1529	hidnplayr	335	cmp esi, 20 + 12 ; Timestamp option is 12 bytes
1514	hidnplayr	336	jl .no_timestamp
		337	je .is_ok
		338
1529	hidnplayr	339	cmp byte [edx + TCP_segment.Data + 12], TCP_OPT_EOL ; end of option list
1514	hidnplayr	340	jne .no_timestamp
		341
		342	.is_ok:
		343	test [edx + TCP_segment.Flags], TH_SYN ; SYN flag must not be set
		344	jnz .no_timestamp
		345
		346	cmp dword [edx + TCP_segment.Data], 0x0101080a ; Timestamp header
		347	jne .no_timestamp
		348
		349	DEBUGF 1,"timestamp ok\n"
		350
1529	hidnplayr	351	; TODO: Parse the option
1514	hidnplayr	352	; TODO: Set a Bit in the TCP to tell all options are parsed
		353
		354	.no_timestamp:
		355
		356	;-------------------------------------------
		357	; Convert Big-endian values to little endian
		358
1543	hidnplayr	359	ntohd [edx + TCP_segment.SequenceNumber]
		360	ntohd [edx + TCP_segment.AckNumber]
1514	hidnplayr	361
1543	hidnplayr	362	ntohw [edx + TCP_segment.Window]
		363	ntohw [edx + TCP_segment.UrgentPointer]
		364	ntohw [edx + TCP_segment.SourcePort]
		365	ntohw [edx + TCP_segment.DestinationPort]
1514	hidnplayr	366
		367	;------------------------------------------------------------
		368	; Next thing to do is find the TCB (thus, the socket pointer)
		369
1274	hidnplayr	370	; IP Packet TCP Destination Port = local Port
1514	hidnplayr	371	; (IP Packet SenderAddress = Remote IP) OR (Remote IP = 0)
1318	hidnplayr	372	; (IP Packet TCP Source Port = remote Port) OR (remote Port = 0)
1159	hidnplayr	373
		374	mov ebx, net_sockets
		375
1249	hidnplayr	376	.socket_loop:
1514	hidnplayr	377	mov ebx, [ebx + SOCKET.NextPtr]
1159	hidnplayr	378	or ebx, ebx
1514	hidnplayr	379	jz .drop_with_reset
1159	hidnplayr	380
1543	hidnplayr	381	cmp [ebx + SOCKET.Domain], AF_INET4
1249	hidnplayr	382	jne .socket_loop
1159	hidnplayr	383
1543	hidnplayr	384	cmp [ebx + SOCKET.Protocol], IP_PROTO_TCP
		385	jne .socket_loop
		386
1514	hidnplayr	387	mov ax, [edx + TCP_segment.DestinationPort]
		388	cmp [ebx + TCP_SOCKET.LocalPort], ax
		389	jne .socket_loop
		390
		391	mov eax, [ebx + IP_SOCKET.RemoteIP]
1543	hidnplayr	392	cmp eax, edi ; edi is source ip from packet
1249	hidnplayr	393	je @f
		394	test eax, eax
1514	hidnplayr	395	jnz .socket_loop
1249	hidnplayr	396	@@:
1159	hidnplayr	397
1514	hidnplayr	398	mov ax, [ebx + TCP_SOCKET.RemotePort]
		399	cmp [edx + TCP_segment.SourcePort] , ax
1274	hidnplayr	400	je .found_socket
1249	hidnplayr	401	test ax, ax
1254	hidnplayr	402	jnz .socket_loop
1274	hidnplayr	403	.found_socket:
1529	hidnplayr	404	DEBUGF 1,"Socket ptr: %x\n", ebx
1254	hidnplayr	405
1514	hidnplayr	406	; ebx now contains the pointer to the socket
1257	hidnplayr	407
1514	hidnplayr	408	;----------------------------
		409	; Check if socket isnt closed
		410
1529	hidnplayr	411	cmp [ebx + TCP_SOCKET.t_state], TCB_CLOSED
1514	hidnplayr	412	je .drop
		413
		414	;----------------
		415	; Lock the socket
		416
1529	hidnplayr	417	;; add ebx, SOCKET.lock ; TODO: figure out if we should lock now already
		418	;; call wait_mutex
		419	;; sub ebx, SOCKET.lock
1159	hidnplayr	420
1529	hidnplayr	421	DEBUGF 1,"Socket locked\n"
1159	hidnplayr	422
1543	hidnplayr	423	;---------------------------------------
		424	; unscale the window into a 32 bit value
1529	hidnplayr	425
1514	hidnplayr	426	movzx eax, [edx + TCP_segment.Window]
1534	hidnplayr	427	push ecx
1529	hidnplayr	428	mov cl, [ebx + TCP_SOCKET.SND_SCALE]
1514	hidnplayr	429	shl eax, cl
1543	hidnplayr	430	mov dword [edx + TCP_segment.Window], eax ; word after window is checksum, we dont need checksum anymore
1534	hidnplayr	431	pop ecx
1514	hidnplayr	432
		433	;-----------------------------------
		434	; Is this socket a listening socket?
		435
1533	hidnplayr	436	test [ebx + SOCKET.options], SO_ACCEPTCON
1543	hidnplayr	437	jz .no_listening_socket
1514	hidnplayr	438
1543	hidnplayr	439	call SOCKET_fork
		440	jz .drop
		441
		442	push [edx + TCP_segment.DestinationPort]
		443	pop [eax + TCP_SOCKET.LocalPort]
		444
		445	push [edx - IPv4_Packet.DataOrOptional + IPv4_Packet.DestinationAddress] ;;; FIXME
		446	pop [eax + IP_SOCKET.LocalIP]
		447
		448	push [edx - IPv4_Packet.DataOrOptional + IPv4_Packet.SourceAddress] ;;; FIXME
		449	pop [eax + IP_SOCKET.RemoteIP]
		450
		451	mov [eax + TCP_SOCKET.t_state], TCB_LISTEN
		452
		453	jmp .not_uni_xfer
		454
		455	.no_listening_socket:
		456
1529	hidnplayr	457	;-------------------------------------
		458	; Reset idle timer and keepalive timer
1514	hidnplayr	459
1529	hidnplayr	460	mov [ebx + TCP_SOCKET.t_idle], 0
		461	mov [ebx + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval
1514	hidnplayr	462
1529	hidnplayr	463	;--------------------
		464	; Process TCP options
1514	hidnplayr	465
1529	hidnplayr	466	cmp esi, 20 ; esi is headersize
		467	je .no_options
1514	hidnplayr	468
1529	hidnplayr	469	DEBUGF 1,"Segment has options\n"
1514	hidnplayr	470
1530	hidnplayr	471	cmp [ebx + TCP_SOCKET.t_state], TCB_LISTEN ; no options when in listen state
1543	hidnplayr	472	jz .not_uni_xfer ; also no header prediction
1514	hidnplayr	473
1529	hidnplayr	474	lea edi, [edx + TCP_segment.Data]
		475	lea eax, [edx + esi]
1514	hidnplayr	476
1529	hidnplayr	477	.opt_loop:
		478	cmp edi, eax
		479	jge .no_options
1514	hidnplayr	480
1529	hidnplayr	481	cmp byte [edi], TCP_OPT_EOL ; end of option list?
		482	jz .no_options
1514	hidnplayr	483
1529	hidnplayr	484	cmp byte [edi], TCP_OPT_NOP ; nop ?
		485	jz .opt_nop
1514	hidnplayr	486
1529	hidnplayr	487	cmp byte [edi], TCP_OPT_MAXSEG
		488	je .opt_maxseg
1514	hidnplayr	489
1529	hidnplayr	490	cmp byte [edi], TCP_OPT_WINDOW
		491	je .opt_window
1514	hidnplayr	492
1529	hidnplayr	493	cmp byte [edi], TCP_OPT_TIMESTAMP
		494	je .opt_timestamp
1514	hidnplayr	495
1529	hidnplayr	496	jmp .no_options ; If we reach here, some unknown options were received, skip them all!
1514	hidnplayr	497
1529	hidnplayr	498	.opt_nop:
		499	inc edi
		500	jmp .opt_loop
1514	hidnplayr	501
1529	hidnplayr	502	.opt_maxseg:
		503	cmp byte [edi+1], 4
		504	jne .no_options ; error occured, ignore all options!
1514	hidnplayr	505
1529	hidnplayr	506	test [edx + TCP_segment.Flags], TH_SYN
		507	jz @f
		508
1530	hidnplayr	509	movzx eax, word[edi+2]
		510	rol ax, 8
1533	hidnplayr	511	DEBUGF 1,"Maxseg: %u\n", ax
1529	hidnplayr	512
1530	hidnplayr	513	mov [ebx + TCP_SOCKET.t_maxseg], eax
		514
1529	hidnplayr	515	@@:
		516	add edi, 4
		517	jmp .opt_loop
		518
		519
		520	.opt_window:
		521	cmp byte [edi+1], 3
		522	jne .no_options
		523
		524	test [edx + TCP_segment.Flags], TH_SYN
		525	jz @f
		526
1533	hidnplayr	527	DEBUGF 1,"Got window option\n"
1529	hidnplayr	528
		529	;;;;;
		530	@@:
		531	add edi, 3
		532	jmp .opt_loop
		533
		534
		535	.opt_timestamp:
		536	cmp byte [edi+1], 10
		537	jne .no_options
		538
1533	hidnplayr	539	DEBUGF 1,"Got timestamp option\n"
1529	hidnplayr	540
		541	;;;;;
		542
		543	add edi, 10
		544	jmp .opt_loop
		545
		546	.no_options:
		547
1514	hidnplayr	548	;-----------------------------------------------------------------------
		549	; Time to do some header prediction (Original Principle by Van Jacobson)
		550
		551	; There are two common cases for an uni-directional data transfer.
		552	;
		553	; General rule: the packets has no control flags, is in-sequence,
		554	; window width didnt change and we're not retransmitting.
		555	;
		556	; Second rules:
		557	; - If the length is 0 and the ACK moved forward, we're the sender side of the transfer.
		558	; In this case we'll free the ACK'ed data and notify higher levels that we have free space in buffer
		559	;
		560	; - If the length is not 0 and the ACK didn't move, we're the receiver side of the transfer.
		561	; If the packets are in order (data queue is empty), add the data to the socket buffer and request a delayed ACK
		562
1529	hidnplayr	563	cmp [ebx + TCP_SOCKET.t_state], TCB_ESTABLISHED
1514	hidnplayr	564	jnz .not_uni_xfer
		565
1529	hidnplayr	566	test [edx + TCP_segment.Flags], TH_SYN + TH_FIN + TH_RST + TH_URG
1514	hidnplayr	567	jnz .not_uni_xfer
		568
1529	hidnplayr	569	test [edx + TCP_segment.Flags], TH_ACK
1514	hidnplayr	570	jz .not_uni_xfer
		571
		572	mov eax, [edx + TCP_segment.SequenceNumber]
		573	cmp eax, [ebx + TCP_SOCKET.RCV_NXT]
		574	jne .not_uni_xfer
		575
1543	hidnplayr	576	mov eax, dword [edx + TCP_segment.Window]
1536	hidnplayr	577	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		578	jne .not_uni_xfer
1514	hidnplayr	579
		580	mov eax, [ebx + TCP_SOCKET.SND_NXT]
		581	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		582	jne .not_uni_xfer
		583
		584	;---------------------------------------
		585	; check if we are sender in the uni-xfer
		586
		587	; If the following 4 conditions are all true, this segment is a pure ACK.
		588	;
1529	hidnplayr	589	; - The segment contains no data.
		590	test ecx, ecx
1514	hidnplayr	591	jnz .not_sender
1274	hidnplayr	592
1529	hidnplayr	593	; - The congestion window is greater than or equal to the current send window.
1514	hidnplayr	594	; 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.
		595	mov eax, [ebx + TCP_SOCKET.SND_CWND]
		596	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		597	jl .not_uni_xfer
1318	hidnplayr	598
1529	hidnplayr	599	; - The acknowledgment field in the segment is less than or equal to the maximum sequence number sent.
1534	hidnplayr	600	mov eax, [edx + TCP_segment.AckNumber]
		601	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
1529	hidnplayr	602	jg .not_uni_xfer
		603
		604	; - The acknowledgment field in the segment is greater than the largest unacknowledged sequence number.
1534	hidnplayr	605	sub eax, [ebx + TCP_SOCKET.SND_UNA]
1529	hidnplayr	606	jle .not_uni_xfer
		607
1514	hidnplayr	608	DEBUGF 1,"Header prediction: we are sender\n"
1274	hidnplayr	609
1514	hidnplayr	610	;---------------------------------
		611	; Packet is a pure ACK, process it
1274	hidnplayr	612
1514	hidnplayr	613	; Update RTT estimators
1159	hidnplayr	614
1514	hidnplayr	615	; Delete acknowledged bytes from send buffer
1536	hidnplayr	616	mov ecx, eax
1533	hidnplayr	617	lea eax, [ebx + STREAM_SOCKET.snd]
1529	hidnplayr	618	call SOCKET_ring_free
		619
1536	hidnplayr	620	; update window pointers
		621	mov eax, [edx + TCP_segment.AckNumber]
		622	dec eax
		623	mov [ebx + TCP_SOCKET.SND_WL1], eax
		624
1514	hidnplayr	625	; Stop retransmit timer
1519	hidnplayr	626	mov [ebx + TCP_SOCKET.timer_ack], 0
1159	hidnplayr	627
1514	hidnplayr	628	; Awaken waiting processes
1519	hidnplayr	629	mov eax, ebx
		630	call SOCKET_notify_owner
1318	hidnplayr	631
1536	hidnplayr	632	;; Generate more output
		633	;; mov eax, ebx
		634	;; call TCP_output
		635	;;
		636	;; jmp .drop
		637	jmp .step6
1254	hidnplayr	638
1514	hidnplayr	639	;-------------------------------------------------
		640	; maybe we are the receiver in the uni-xfer then..
		641
		642	.not_sender:
1529	hidnplayr	643	; - The amount of data in the segment is greater than 0 (data count is in ecx)
1514	hidnplayr	644
1529	hidnplayr	645	; - The acknowledgment field equals the largest unacknowledged sequence number. This means no data is acknowledged by this segment.
1514	hidnplayr	646	mov eax, [edx + TCP_segment.AckNumber]
		647	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
		648	jne .not_uni_xfer
		649
1529	hidnplayr	650	; - The reassembly list of out-of-order segments for the connection is empty (seg_next equals tp). ;;;;;;;
1514	hidnplayr	651
		652	jnz .not_uni_xfer
		653
		654	;-------------------------------------
		655	; Complete processing of received data
		656
		657	DEBUGF 1,"header prediction: we are receiver\nreceiving %u bytes of data\n", ecx
		658
1529	hidnplayr	659	add esi, edx
1533	hidnplayr	660	lea eax, [ebx + STREAM_SOCKET.rcv]
		661	call SOCKET_ring_write ; Add the data to the socket buffer
1514	hidnplayr	662
1533	hidnplayr	663	mov eax, ebx
		664	call SOCKET_notify_owner
		665
1529	hidnplayr	666	add [ebx + TCP_SOCKET.RCV_NXT], ecx ; Update sequence number with number of bytes we have copied
		667	or [ebx + TCP_SOCKET.t_flags], TF_DELACK ; Set delayed ack flag
1514	hidnplayr	668
		669	jmp .drop
		670
		671	;----------------------------------------------------
1529	hidnplayr	672	; Header prediction failed, doing it the slow way.. ;;;;; current implementation of header prediction destroys some regs (ecx) !!
1514	hidnplayr	673
		674	.not_uni_xfer:
		675
1533	hidnplayr	676	DEBUGF 1,"Header prediction failed\n" ; time to do it the "slow" way :)
1514	hidnplayr	677
		678	;------------------------------
		679	; Calculate receive window size
		680
		681	;;;;
		682
1529	hidnplayr	683	cmp [ebx + TCP_SOCKET.t_state], TCB_LISTEN
1514	hidnplayr	684	je .LISTEN
		685
1529	hidnplayr	686	cmp [ebx + TCP_SOCKET.t_state], TCB_SYN_SENT
1514	hidnplayr	687	je .SYN_SENT
		688
		689	;--------------------------------------------
		690	; Protection Against Wrapped Sequence Numbers
		691
1533	hidnplayr	692	; First, check if timestamp is present
1514	hidnplayr	693
		694	;;;; TODO
		695
		696	; Then, check if at least some bytes of data are within window
		697
		698	;;;; TODO
		699
		700	jmp .trim_then_step6
		701
1529	hidnplayr	702	;-------------
		703	; Passive Open
		704
1249	hidnplayr	705	align 4
1514	hidnplayr	706	.LISTEN:
1196	hidnplayr	707
1514	hidnplayr	708	DEBUGF 1,"TCP state: listen\n"
1159	hidnplayr	709
1543	hidnplayr	710	test [edx + TCP_segment.Flags], TH_RST ;;; TODO: kill new socket on error
1514	hidnplayr	711	jnz .drop
1159	hidnplayr	712
1514	hidnplayr	713	test [edx + TCP_segment.Flags], TH_ACK
		714	jnz .drop_with_reset
1159	hidnplayr	715
1514	hidnplayr	716	test [edx + TCP_segment.Flags], TH_SYN
		717	jz .drop
1159	hidnplayr	718
1533	hidnplayr	719
1514	hidnplayr	720	; TODO: check if it's a broadcast or multicast, and drop if so
1159	hidnplayr	721
1529	hidnplayr	722	;-----------------------
		723	; Fill in some variables
1514	hidnplayr	724
1529	hidnplayr	725	add [TCP_sequence_num], 64000
1514	hidnplayr	726
1529	hidnplayr	727	push [edx + TCP_segment.SourcePort]
		728	pop [eax + TCP_SOCKET.RemotePort]
1514	hidnplayr	729
1529	hidnplayr	730	push [edx + TCP_segment.SequenceNumber]
		731	pop [eax + TCP_SOCKET.IRS]
1159	hidnplayr	732
1529	hidnplayr	733	push [eax + TCP_SOCKET.ISS]
		734	pop [eax + TCP_SOCKET.SND_NXT]
1159	hidnplayr	735
1543	hidnplayr	736	TCP_sendseqinit eax
		737	TCP_rcvseqinit eax
		738
1529	hidnplayr	739	mov [eax + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		740	mov [eax + TCP_SOCKET.t_flags], TF_ACKNOW
1543	hidnplayr	741	mov [eax + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval ;;;; macro
1159	hidnplayr	742
1543	hidnplayr	743	add eax, STREAM_SOCKET.snd
		744	call SOCKET_ring_create
		745
		746	add eax, STREAM_SOCKET.rcv - STREAM_SOCKET.snd
		747	call SOCKET_ring_create
		748
		749	sub eax, STREAM_SOCKET.rcv
		750
		751	mov [eax + SOCKET.lock], 0
		752	mov ebx, eax ; if there is data, it must arrive in this new socket!
1514	hidnplayr	753	jmp .trim_then_step6
1159	hidnplayr	754
1254	hidnplayr	755
1529	hidnplayr	756	;------------
		757	; Active Open
1159	hidnplayr	758
1514	hidnplayr	759	align 4
		760	.SYN_SENT:
1281	hidnplayr	761
1514	hidnplayr	762	DEBUGF 1,"TCP state: syn_sent\n"
1159	hidnplayr	763
1514	hidnplayr	764	test [edx + TCP_segment.Flags], TH_ACK
		765	jz @f
1281	hidnplayr	766
1514	hidnplayr	767	mov eax, [edx + TCP_segment.AckNumber]
		768	cmp eax, [ebx + TCP_SOCKET.ISS]
		769	jle .drop_with_reset
1281	hidnplayr	770
1529	hidnplayr	771	; mov eax, [edx + TCP_segment.AckNumber]
1533	hidnplayr	772	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		773	jg .drop_with_reset
1514	hidnplayr	774	@@:
1281	hidnplayr	775
1514	hidnplayr	776	test [edx + TCP_segment.Flags], TH_RST
		777	jz @f
1281	hidnplayr	778
1514	hidnplayr	779	test [edx + TCP_segment.Flags], TH_ACK
		780	jz .drop
1281	hidnplayr	781
1514	hidnplayr	782	;tp = tcp_drop(tp, ECONNREFUSED)
1159	hidnplayr	783
1514	hidnplayr	784	jmp .drop
		785	@@:
1159	hidnplayr	786
1514	hidnplayr	787	test [edx + TCP_segment.Flags], TH_SYN
		788	jz .drop
1318	hidnplayr	789
1529	hidnplayr	790	; at this point, segment seems to be valid
		791
1514	hidnplayr	792	test [edx + TCP_segment.Flags], TH_ACK
1529	hidnplayr	793	jz .no_syn_ack
1514	hidnplayr	794
1529	hidnplayr	795	; now, process received SYN in response to an active open
		796
1514	hidnplayr	797	mov eax, [edx + TCP_segment.AckNumber]
		798	mov [ebx + TCP_SOCKET.SND_UNA], eax
		799	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		800	jle @f
		801	mov [ebx + TCP_SOCKET.SND_NXT], eax
1529	hidnplayr	802	@@:
1514	hidnplayr	803
1529	hidnplayr	804	.no_syn_ack:
1514	hidnplayr	805
1529	hidnplayr	806	mov [ebx + TCP_SOCKET.timer_retransmission], 0 ; disable retransmission
1514	hidnplayr	807
1529	hidnplayr	808	push [edx + TCP_segment.SequenceNumber]
		809	pop [ebx + TCP_SOCKET.IRS]
		810
1533	hidnplayr	811	TCP_rcvseqinit ebx
1529	hidnplayr	812
		813	mov [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
		814
		815	mov eax, [ebx + TCP_SOCKET.SND_UNA]
		816	cmp eax, [ebx + TCP_SOCKET.ISS]
		817	jle .simultaneous_open
		818
		819	test [edx + TCP_segment.Flags], TH_ACK
		820	jz .simultaneous_open
		821
		822	DEBUGF 1,"TCP: active open\n"
		823
		824	; TODO: update stats
1533	hidnplayr	825	; TODO: set general socket state to connected
1514	hidnplayr	826
		827	mov [ebx + TCP_SOCKET.t_state], TCB_ESTABLISHED
		828
		829	; TODO: check if we should scale the connection (567-572)
		830	; TODO: update RTT estimators
		831
1529	hidnplayr	832	jmp .trimthenstep6
1514	hidnplayr	833
1529	hidnplayr	834	.simultaneous_open:
1514	hidnplayr	835
1529	hidnplayr	836	DEBUGF 1,"TCP: simultaneous open\n"
1514	hidnplayr	837	; We have received a syn but no ACK, so we are having a simultaneous open..
		838	mov [ebx + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		839
		840	;-------------------------------------
		841	; Common processing for receipt of SYN
		842
		843	.trimthenstep6:
		844
		845	inc [edx + TCP_segment.SequenceNumber]
		846
		847	cmp cx, [ebx + TCP_SOCKET.RCV_WND]
		848	jle @f
		849
		850	movzx eax, cx
		851	sub ax, [ebx + TCP_SOCKET.RCV_WND]
		852	; TODO: 592
		853	mov cx, [ebx + TCP_SOCKET.RCV_WND]
		854	; TODO...
		855	@@:
		856	;;;;;
1529	hidnplayr	857	jmp .step6
1514	hidnplayr	858
		859
1529	hidnplayr	860	.trim_then_step6:
1159	hidnplayr	861
1514	hidnplayr	862	;----------------------------
		863	; trim any data not in window
1159	hidnplayr	864
1533	hidnplayr	865	DEBUGF 1,"Trimming window\n"
		866
1514	hidnplayr	867	mov eax, [ebx + TCP_SOCKET.RCV_NXT]
		868	sub eax, [edx + TCP_segment.SequenceNumber]
1318	hidnplayr	869
1514	hidnplayr	870	test eax, eax
1533	hidnplayr	871	jz .no_duplicate
1274	hidnplayr	872
1514	hidnplayr	873	test [edx + TCP_segment.Flags], TH_SYN
		874	jz .no_drop
		875
		876	and [edx + TCP_segment.Flags], not (TH_SYN)
		877	inc [edx + TCP_segment.SequenceNumber]
		878
		879	cmp [edx + TCP_segment.UrgentPointer], 1
		880	jl @f
		881
		882	dec [edx + TCP_segment.UrgentPointer]
		883
		884	jmp .no_drop
		885	@@:
		886
		887	and [edx + TCP_segment.Flags], not (TH_URG)
		888	dec eax
1533	hidnplayr	889	jz .no_duplicate
1514	hidnplayr	890	.no_drop:
		891
1533	hidnplayr	892	DEBUGF 1,"Going to drop %u out of %u bytes\n", eax, ecx
1529	hidnplayr	893
1514	hidnplayr	894	; eax holds number of bytes to drop
		895
		896	;----------------------------------
		897	; Check for entire duplicate packet
		898
		899	cmp eax, ecx
		900	jge .duplicate
		901
		902	;;; TODO: figure 28.30
		903
		904	;------------------------
		905	; Check for duplicate FIN
		906
		907	test [edx + TCP_segment.Flags], TH_FIN
		908	jz @f
		909	inc ecx
		910	cmp eax, ecx
		911	dec ecx
		912	jne @f
		913
		914	mov eax, ecx
		915	and [edx + TCP_segment.Flags], not TH_FIN
1529	hidnplayr	916	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1514	hidnplayr	917	jmp .no_duplicate
		918	@@:
		919
		920	; Handle the case when a bound socket connects to itself
		921	; Allow packets with a SYN and an ACKto continue with the processing
		922
		923	;-------------------------------------
		924	; Generate duplicate ACK if nescessary
		925
		926	; This code also handles simultaneous half-open or self-connects
		927
		928	test eax, eax
		929	jnz .drop_after_ack
		930
		931	cmp [edx + TCP_segment.Flags], TH_ACK
		932	jz .drop_after_ack
		933
		934	.duplicate:
		935
1533	hidnplayr	936	DEBUGF 1,"Duplicate received\n"
1529	hidnplayr	937
1514	hidnplayr	938	;----------------------------------------
		939	; Update statistics for duplicate packets
		940
		941	;;; TODO
		942
1529	hidnplayr	943	jmp .drop ;;; DROP the packet ??
1514	hidnplayr	944
		945	.no_duplicate:
		946
		947	;-----------------------------------------------
		948	; Remove duplicate data and update urgent offset
		949
		950	add [edx + TCP_segment.SequenceNumber], eax
		951
		952	;;; TODO
		953
		954	sub [edx + TCP_segment.UrgentPointer], ax
		955	jg @f
		956
		957	and [edx + TCP_segment.Flags], not (TH_URG)
		958	mov [edx + TCP_segment.UrgentPointer], 0
		959	@@:
		960
		961	;--------------------------------------------------
		962	; Handle data that arrives after process terminates
		963
		964	cmp [ebx + SOCKET.PID], 0
1533	hidnplayr	965	jg @f
1514	hidnplayr	966
		967	cmp [ebx + TCP_SOCKET.t_state], TCB_CLOSE_WAIT
		968	jle @f
		969
		970	test ecx, ecx
		971	jz @f
		972
		973	;;; Close the socket
		974	;;; update stats
		975
		976	jmp .drop_with_reset
		977	@@:
		978
		979	;----------------------------------------
		980	; Remove data beyond right edge of window
		981
		982	mov eax, [edx + TCP_segment.SequenceNumber]
		983	add eax, ecx
		984	sub eax, [ebx + TCP_SOCKET.RCV_NXT]
		985	sub ax, [ebx + TCP_SOCKET.RCV_WND]
		986
		987	; eax now holds the number of bytes to drop
		988
		989	jle .no_excess_data
		990
		991	;;; TODO: update stats
		992
		993	cmp eax, ecx
		994	jl .dont_drop_all
		995
		996	;;; TODO 700-736
		997
		998	.dont_drop_all:
		999
		1000	.no_excess_data:
		1001
		1002	;-----------------
		1003	; Record timestamp
		1004
		1005	;;; TODO 737-746
		1006
		1007	;------------------
		1008	; Process RST flags
		1009
		1010	test [edx + TCP_segment.Flags], TH_RST
		1011	jz .rst_skip
		1012
1529	hidnplayr	1013	DEBUGF 1,"Got an RST flag"
		1014
1514	hidnplayr	1015	mov eax, [ebx + TCP_SOCKET.t_state]
		1016	shl eax, 2
		1017	jmp dword [eax + .rst_sw_list]
		1018
		1019	.rst_sw_list:
		1020	dd .rst_skip ;TCB_CLOSED
		1021	dd .rst_skip ;TCB_LISTEN
		1022	dd .rst_skip ;TCB_SYN_SENT
		1023	dd .econnrefused ;TCB_SYN_RECEIVED
		1024	dd .econnreset ;TCB_ESTABLISHED
		1025	dd .econnreset ;TCB_CLOSE_WAIT
		1026	dd .econnreset ;TCB_FIN_WAIT_1
		1027	dd .rst_close ;TCB_CLOSING
		1028	dd .rst_close ;TCB_LAST_ACK
		1029	dd .econnreset ;TCB_FIN_WAIT_2
		1030	dd .rst_close ;TCB_TIMED_WAIT
		1031
		1032	.econnrefused:
		1033
1529	hidnplayr	1034	DEBUGF 1,"Connection refused"
		1035
1514	hidnplayr	1036	;;; TODO: debug info
		1037
		1038	jmp .close
		1039
		1040	.econnreset:
		1041
1529	hidnplayr	1042	DEBUGF 1,"Connection reset"
		1043
1514	hidnplayr	1044	;;; TODO: debug info
1529	hidnplayr	1045	.close:
1514	hidnplayr	1046
1529	hidnplayr	1047	DEBUGF 1,"Closing connection"
		1048
1514	hidnplayr	1049	;;; update stats
		1050
		1051	.rst_close:
		1052
1534	hidnplayr	1053	DEBUGF 1,"Closing with reset\n"
1529	hidnplayr	1054
1514	hidnplayr	1055	;;; Close the socket
		1056	jmp .drop
		1057
		1058	.rst_skip:
		1059
		1060	;--------------------------------------
		1061	; handle SYN-full and ACK-less segments
		1062
		1063	test [edx + TCP_segment.Flags], TH_SYN
		1064	jz @f
		1065
		1066	;;; tcp_drop ( ECONNRESET)
		1067	jmp .drop_with_reset
		1068
		1069	test [edx + TCP_segment.Flags], TH_ACK
		1070	jz .drop
1534	hidnplayr	1071	@@:
1514	hidnplayr	1072	;----------------
		1073	; Process the ACK
		1074
		1075	cmp [ebx + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		1076	jg .ack_dup
		1077	jl .ack_nodup
		1078
1534	hidnplayr	1079	DEBUGF 1,"TCP state = syn received\n"
1533	hidnplayr	1080
1514	hidnplayr	1081	;;;;;
		1082
1536	hidnplayr	1083	.ack_nodup:
1514	hidnplayr	1084
1536	hidnplayr	1085	DEBUGF 1,"New ACK\n"
1533	hidnplayr	1086
1514	hidnplayr	1087
		1088
1536	hidnplayr	1089	.ack_dup:
1514	hidnplayr	1090
1536	hidnplayr	1091	;;;;
1533	hidnplayr	1092
1514	hidnplayr	1093	;-------------------------------------------------
1519	hidnplayr	1094	; If the congestion window was inflated to account
1514	hidnplayr	1095	; for the other side's cached packets, retrace it
		1096
		1097	;;;; 888 - 902
		1098
		1099
		1100	;------------------------------------------
		1101	; RTT measurements and retransmission timer
		1102
		1103	;;;;; 903 - 926
		1104
1519	hidnplayr	1105	mov [ebx + TCP_SOCKET.timer_retransmission], 0
1514	hidnplayr	1106
1519	hidnplayr	1107	mov eax, [ebx + TCP_SOCKET.SND_MAX]
		1108	cmp eax, [edx + TCP_segment.AckNumber]
		1109	je .all_outstanding
1543	hidnplayr	1110	mov [ebx + TCP_SOCKET.timer_retransmission], 120 ;;;; TODO: correct this value (use a macro for it)
1519	hidnplayr	1111	.all_outstanding:
		1112
1514	hidnplayr	1113	;-------------------------------------------
		1114	; Open congestion window in response to ACKs
		1115
		1116	;;;;
		1117
		1118
		1119	;------------------------------------------
		1120	; Remove acknowledged data from send buffer
		1121
1536	hidnplayr	1122	pusha
		1123	; Delete acknowledged bytes from send buffer
		1124	mov ecx, [edx + TCP_segment.AckNumber]
		1125	sub ecx, [ebx + TCP_SOCKET.SND_UNA]
1533	hidnplayr	1126	lea eax, [ebx + STREAM_SOCKET.snd]
1536	hidnplayr	1127	call SOCKET_ring_free
		1128	popa
1514	hidnplayr	1129
1536	hidnplayr	1130
		1131	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; code missing (943?)
		1132
1542	hidnplayr	1133
		1134
1536	hidnplayr	1135	mov eax, [edx + TCP_segment.AckNumber]
		1136	mov [ebx + TCP_SOCKET.SND_UNA], eax
		1137
		1138	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		1139	jl @f
		1140	mov [ebx + TCP_SOCKET.SND_NXT], eax
		1141	@@:
		1142
		1143
1514	hidnplayr	1144	;---------------------------------------
		1145	; Wake up process waiting on send buffer
		1146
1529	hidnplayr	1147	mov eax, ebx
		1148	call SOCKET_notify_owner
1514	hidnplayr	1149
		1150	mov eax, [ebx + TCP_SOCKET.t_state]
		1151	shl eax, 2
		1152	jmp dword [eax + .ACK_sw_list]
		1153
		1154	.ACK_sw_list:
		1155	dd .step6 ;TCB_CLOSED
		1156	dd .step6 ;TCB_LISTEN
		1157	dd .step6 ;TCB_SYN_SENT
		1158	dd .step6 ;TCB_SYN_RECEIVED
		1159	dd .step6 ;TCB_ESTABLISHED
		1160	dd .step6 ;TCB_CLOSE_WAIT
		1161	dd ._963 ;TCB_FIN_WAIT_1
		1162	dd ._958 ;TCB_CLOSING
		1163	dd ._999 ;TCB_LAST_ACK
		1164	dd .step6 ;TCB_FIN_WAIT_2
		1165	dd ._1010 ;TCB_TIMED_WAIT
		1166
		1167
1536	hidnplayr	1168	._963:
1514	hidnplayr	1169
		1170
		1171	jmp .step6
		1172
		1173
1536	hidnplayr	1174	._958:
1514	hidnplayr	1175
		1176	jmp .step6
		1177
1536	hidnplayr	1178	._999:
1514	hidnplayr	1179
		1180	jmp .step6
		1181
		1182
1536	hidnplayr	1183	._1010:
1514	hidnplayr	1184
		1185	jmp .step6
		1186
		1187
1536	hidnplayr	1188	.step6:
1514	hidnplayr	1189
		1190	DEBUGF 1,"step 6\n"
		1191
1536	hidnplayr	1192	;----------------------------------------------
		1193	; check if we need to update window information
1514	hidnplayr	1194
		1195	test [edx + TCP_segment.Flags], TH_ACK
		1196	jz .no_window_update
		1197
		1198	mov eax, [ebx + TCP_SOCKET.SND_WL1]
		1199	cmp eax, [edx + TCP_segment.SequenceNumber]
1536	hidnplayr	1200	jl .update_window
		1201	jg @f
1514	hidnplayr	1202
		1203	mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1204	cmp eax, [edx + TCP_segment.AckNumber]
1536	hidnplayr	1205	jl .update_window
		1206	jg .no_window_update
		1207	@@:
1514	hidnplayr	1208
1543	hidnplayr	1209	mov eax, [ebx + TCP_SOCKET.SND_WL2]
1536	hidnplayr	1210	cmp eax, [edx + TCP_segment.AckNumber]
		1211	jne .no_window_update
		1212
		1213	movzx eax, [edx + TCP_segment.Window]
1514	hidnplayr	1214	cmp eax, [ebx + TCP_SOCKET.SND_WND]
1536	hidnplayr	1215	jle .no_window_update
1514	hidnplayr	1216
1536	hidnplayr	1217	.update_window:
1514	hidnplayr	1218
1536	hidnplayr	1219	DEBUGF 1,"Updating window\n"
1514	hidnplayr	1220
1536	hidnplayr	1221	;----------------------------------
		1222	; Keep track of pure window updates
		1223
		1224	; test ecx, ecx
		1225	; jz @f
		1226	;
		1227	; mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1228	; cmp eax, [edx + TCP_segment.AckNumber]
		1229	; jne @f
		1230	;
		1231	; ;; mov eax, tiwin
		1232	; cmp eax, [ebx + TCP_SOCKET.SND_WND]
		1233	; jle @f
		1234	;
		1235	; ;;; update stats
		1236	;
		1237	; @@:
		1238
1543	hidnplayr	1239	mov eax, dword [edx + TCP_segment.Window]
1514	hidnplayr	1240	cmp eax, [ebx + TCP_SOCKET.max_sndwnd]
		1241	jle @f
		1242	mov [ebx + TCP_SOCKET.max_sndwnd], eax
		1243	@@:
		1244	mov [ebx + TCP_SOCKET.SND_WND], eax
		1245
1536	hidnplayr	1246	push [edx + TCP_segment.SequenceNumber]
		1247	pop [ebx + TCP_SOCKET.SND_WL1]
1514	hidnplayr	1248
1536	hidnplayr	1249	push [edx + TCP_segment.AckNumber]
		1250	pop [ebx + TCP_SOCKET.SND_WL2]
1514	hidnplayr	1251
		1252	;;; needoutput = 1
		1253
		1254	.no_window_update:
		1255
		1256	;-----------------
		1257	; process URG flag
		1258
		1259	test [edx + TCP_segment.Flags], TH_URG
		1260	jz .not_urgent
		1261
		1262	cmp [edx + TCP_segment.UrgentPointer], 0
		1263	jz .not_urgent
		1264
		1265	cmp [ebx + TCP_SOCKET.t_state], TCB_TIMED_WAIT
		1266	je .not_urgent
		1267
		1268	; Ignore bogus urgent offsets
		1269
		1270	;;; 1040-1050
		1271
		1272	movzx eax, [edx + TCP_segment.UrgentPointer]
1533	hidnplayr	1273	add eax, [ebx + STREAM_SOCKET.rcv + RING_BUFFER.size]
1514	hidnplayr	1274	cmp eax, SOCKET_MAXDATA
		1275	jle .not_urgent
		1276
		1277	mov [edx + TCP_segment.UrgentPointer], 0
		1278	and [edx + TCP_segment.Flags], not (TH_URG)
		1279	jmp .do_data
		1280
		1281	.not_urgent:
		1282
		1283	;--------------------------------------
		1284	; processing of received urgent pointer
		1285
1529	hidnplayr	1286	;;; TODO (1051-1093)
1514	hidnplayr	1287
1529	hidnplayr	1288	;--------------------------------
		1289	; process the data in the segment
1514	hidnplayr	1290
1529	hidnplayr	1291	.do_data:
1514	hidnplayr	1292
1534	hidnplayr	1293	DEBUGF 1,"TCP: do data (%u)\n", ecx
1514	hidnplayr	1294
		1295	test [edx + TCP_segment.Flags], TH_FIN
1529	hidnplayr	1296	jnz .process_fin
1514	hidnplayr	1297
1533	hidnplayr	1298	cmp [ebx + TCP_SOCKET.t_state], TCB_FIN_WAIT_1
1514	hidnplayr	1299	jge .dont_do_data
		1300
1533	hidnplayr	1301	test ecx, ecx
		1302	jz .final_processing
		1303
1514	hidnplayr	1304	DEBUGF 1,"Processing data in segment\n"
		1305
1533	hidnplayr	1306	;; TODO: check if data is in sequence !
1514	hidnplayr	1307
1533	hidnplayr	1308	movzx eax, [edx + TCP_segment.DataOffset] ;;; todo: remember this in.. edi ?
		1309	and eax, 0xf0
		1310	shr al, 2
		1311
		1312	lea esi, [edx + eax]
		1313
		1314	or [ebx + TCP_SOCKET.t_flags], TF_DELACK
1543	hidnplayr	1315	add [ebx + TCP_SOCKET.RCV_NXT], ecx
1533	hidnplayr	1316
		1317	lea eax, [ebx + STREAM_SOCKET.rcv]
		1318	call SOCKET_ring_write
		1319
		1320	mov eax, ebx
		1321	call SOCKET_notify_owner
		1322
1514	hidnplayr	1323	jmp .final_processing
		1324
		1325
		1326	.dont_do_data:
		1327
		1328	;---------------
		1329	; FIN processing
		1330
		1331	.process_fin:
		1332
		1333	DEBUGF 1,"Processing FIN\n"
		1334
		1335	mov eax, [ebx + TCP_SOCKET.t_state]
		1336	shl eax, 2
		1337	jmp dword [eax + .FIN_sw_list]
		1338
		1339	.FIN_sw_list:
		1340	dd .no_fin ;TCB_CLOSED
		1341	dd .no_fin ;TCB_LISTEN
		1342	dd .no_fin ;TCB_SYN_SENT
1533	hidnplayr	1343	dd .fin_syn_est ;TCB_SYN_RECEIVED
		1344	dd .fin_syn_est ;TCB_ESTABLISHED
1514	hidnplayr	1345	dd .no_fin ;TCB_CLOSE_WAIT
1533	hidnplayr	1346	dd .fin_wait1 ;TCB_FIN_WAIT_1
1514	hidnplayr	1347	dd .no_fin ;TCB_CLOSING
		1348	dd .no_fin ;TCB_LAST_ACK
1533	hidnplayr	1349	dd .fin_wait2 ;TCB_FIN_WAIT_2
		1350	dd .fin_timed ;TCB_TIMED_WAIT
1514	hidnplayr	1351
		1352
		1353
1533	hidnplayr	1354	.fin_syn_est:
1514	hidnplayr	1355
1533	hidnplayr	1356	jmp .final_processing
1514	hidnplayr	1357
1533	hidnplayr	1358	.fin_wait1:
1514	hidnplayr	1359
1533	hidnplayr	1360	jmp .final_processing
1514	hidnplayr	1361
1533	hidnplayr	1362	.fin_wait2:
1514	hidnplayr	1363
1533	hidnplayr	1364	jmp .final_processing
		1365
		1366	.fin_timed:
		1367
		1368	jmp .final_processing
		1369
1514	hidnplayr	1370	.no_fin:
		1371
		1372	;-----------------
		1373	; Final processing
		1374
		1375	.final_processing:
		1376
		1377	DEBUGF 1,"Final processing\n"
		1378
1533	hidnplayr	1379	mov [ebx + SOCKET.lock], 0
		1380
1514	hidnplayr	1381	;;; if debug enabled, output packet
		1382
		1383	;test ;;;needoutput = 1
		1384	;jnz .outputnow
		1385
		1386	test [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1529	hidnplayr	1387	jnz .ack_now
1514	hidnplayr	1388
1529	hidnplayr	1389	call kernel_free
		1390	add esp, 4
		1391	ret
		1392
		1393	.ack_now:
		1394
		1395	DEBUGF 1,"ACK now!\n"
		1396
		1397	push ebx
		1398	mov eax, ebx
1514	hidnplayr	1399	call TCP_output
1529	hidnplayr	1400	pop ebx
1514	hidnplayr	1401
1274	hidnplayr	1402	call kernel_free
1529	hidnplayr	1403	add esp, 4
		1404	ret
1274	hidnplayr	1405
1514	hidnplayr	1406	;------------------------------------------
		1407	; Generate an ACK, droping incoming segment
1274	hidnplayr	1408
1514	hidnplayr	1409	align 4
		1410	.drop_after_ack:
1274	hidnplayr	1411
1514	hidnplayr	1412	DEBUGF 1,"Drop after ACK\n"
1274	hidnplayr	1413
1514	hidnplayr	1414	test [edx + TCP_segment.Flags], TH_RST
		1415	jnz .drop
1274	hidnplayr	1416
1514	hidnplayr	1417	and [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1274	hidnplayr	1418
1529	hidnplayr	1419	push ebx
		1420	mov eax, ebx
1514	hidnplayr	1421	call TCP_output
1529	hidnplayr	1422	pop ebx
1318	hidnplayr	1423
1514	hidnplayr	1424	call kernel_free
1529	hidnplayr	1425	add esp, 4
		1426	ret
1274	hidnplayr	1427
1514	hidnplayr	1428
		1429	;-------------------------------------------
		1430	; Generate an RST, dropping incoming segment
		1431
		1432	align 4
		1433	.drop_with_reset:
		1434
		1435	DEBUGF 1,"Drop with reset\n"
		1436
		1437	test [edx + TCP_segment.Flags], TH_RST
		1438	jnz .drop
		1439
		1440	;;; if its a multicast/broadcast, also drop
		1441
		1442	test [edx + TCP_segment.Flags], TH_ACK
		1443	jnz .respond_ack
		1444
		1445	test [edx + TCP_segment.Flags], TH_SYN
		1446	jnz .respond_syn
		1447
		1448	call kernel_free
1529	hidnplayr	1449	add esp, 4
		1450	ret
1514	hidnplayr	1451
		1452	.respond_ack:
		1453
1533	hidnplayr	1454	mov dl, TH_RST
1514	hidnplayr	1455
1533	hidnplayr	1456	push ebx
1529	hidnplayr	1457	call TCP_respond_segment
1533	hidnplayr	1458	pop ebx
1514	hidnplayr	1459
		1460	jmp .destroy_new_socket
		1461
		1462
		1463	.respond_syn:
		1464
1533	hidnplayr	1465	mov dl, TH_RST + TH_ACK
1514	hidnplayr	1466
1533	hidnplayr	1467	push ebx
		1468	call TCP_respond_socket
		1469	pop ebx
1514	hidnplayr	1470
		1471	jmp .destroy_new_socket
		1472
		1473	;-----
		1474	; Drop
		1475
		1476	align 4
		1477	.drop:
		1478
		1479	DEBUGF 1,"Dropping packet\n"
		1480
		1481	;;;; If debugging options are enabled, output the packet somwhere
		1482
		1483	.destroy_new_socket:
		1484
		1485	;;;; kill the newly created socket
		1486
		1487	call kernel_free
1529	hidnplayr	1488	add esp, 4
		1489	ret
1514	hidnplayr	1490
		1491
		1492
		1493
		1494
		1495
		1496	;---------------------------
		1497	;
		1498	; TCP_pull_out_of_band
		1499	;
		1500	; IN: eax =
		1501	; ebx = socket ptr
		1502	; edx = tcp packet ptr
		1503	;
		1504	; OUT: /
		1505	;
		1506	;---------------------------
		1507
		1508	align 4
		1509	TCP_pull_out_of_band:
		1510
		1511	DEBUGF 1,"TCP_pull_out_of_band\n"
		1512
		1513	;;;; 1282-1305
		1514
1318	hidnplayr	1515	ret
		1516
		1517
		1518
		1519	;-----------------------------------------------------------------
		1520	;
1514	hidnplayr	1521	; TCP_output
1318	hidnplayr	1522	;
1519	hidnplayr	1523	; IN: eax = socket pointer
1514	hidnplayr	1524	;
1318	hidnplayr	1525	; OUT: /
		1526	;
		1527	;-----------------------------------------------------------------
		1528	align 4
1514	hidnplayr	1529	TCP_output:
1318	hidnplayr	1530
1514	hidnplayr	1531	DEBUGF 1,"TCP_output, socket: %x\n", eax
1318	hidnplayr	1532
1514	hidnplayr	1533	; We'll detect the length of the data to be transmitted, and flags to be used
		1534	; If there is some data, or any critical controls to send (SYN / RST), then transmit
		1535	; Otherwise, investigate further
1318	hidnplayr	1536
1514	hidnplayr	1537	mov ebx, [eax + TCP_SOCKET.SND_MAX]
		1538	cmp ebx, [eax + TCP_SOCKET.SND_UNA]
		1539	jne .not_idle
1318	hidnplayr	1540
1514	hidnplayr	1541	mov ebx, [eax + TCP_SOCKET.t_idle]
		1542	cmp ebx, [eax + TCP_SOCKET.t_rxtcur]
		1543	jle .not_idle
1318	hidnplayr	1544
1514	hidnplayr	1545	; We have been idle for a while and no ACKS are expected to clock out any data we send..
		1546	; Slow start to get ack "clock" running again.
1318	hidnplayr	1547
1514	hidnplayr	1548	mov ebx, [eax + TCP_SOCKET.t_maxseg]
		1549	mov [eax + TCP_SOCKET.SND_CWND], ebx
1318	hidnplayr	1550
1514	hidnplayr	1551	.not_idle:
		1552	.again:
		1553	mov ebx, [eax + TCP_SOCKET.SND_NXT] ; calculate offset
		1554	sub ebx, [eax + TCP_SOCKET.SND_UNA] ;
1318	hidnplayr	1555
1514	hidnplayr	1556	mov ecx, [eax + TCP_SOCKET.SND_WND] ; determine window
		1557	cmp ecx, [eax + TCP_SOCKET.SND_CWND] ;
		1558	jl @f ;
		1559	mov ecx, [eax + TCP_SOCKET.SND_CWND] ;
		1560	@@: ;
1318	hidnplayr	1561
1529	hidnplayr	1562	call TCP_outflags ; in dl
1318	hidnplayr	1563
1514	hidnplayr	1564	; If in persist timeout with window of 0, send 1 byte.
		1565	; Otherwise, if window is small but nonzero, and timer expired,
		1566	; we will send what we can and go to transmit state
1318	hidnplayr	1567
1514	hidnplayr	1568	test [eax + TCP_SOCKET.t_force], -1
		1569	jz .no_persist_timeout
1318	hidnplayr	1570
1514	hidnplayr	1571	test ecx, ecx
		1572	jnz .no_zero_window
1255	hidnplayr	1573
1533	hidnplayr	1574	cmp ebx, [eax + STREAM_SOCKET.snd + RING_BUFFER.size]
1514	hidnplayr	1575	jge @f
1255	hidnplayr	1576
1514	hidnplayr	1577	and dl, not (TH_FIN) ; clear the FIN flag ??? how can it be set before?
1255	hidnplayr	1578
1514	hidnplayr	1579	@@:
		1580	inc ecx
		1581	jmp .no_persist_timeout
1255	hidnplayr	1582
1514	hidnplayr	1583	.no_zero_window:
1254	hidnplayr	1584
1543	hidnplayr	1585	mov [eax + TCP_SOCKET.timer_persist], 0
1514	hidnplayr	1586	mov [eax + TCP_SOCKET.t_rxtshift], 0
1254	hidnplayr	1587
1514	hidnplayr	1588	.no_persist_timeout:
1159	hidnplayr	1589
1514	hidnplayr	1590	;;;106
1159	hidnplayr	1591
1533	hidnplayr	1592	mov esi, [eax + STREAM_SOCKET.snd + RING_BUFFER.size]
1514	hidnplayr	1593	cmp esi, ecx
		1594	jl @f
		1595	mov esi, ecx
		1596	@@:
		1597	sub esi, ebx
1254	hidnplayr	1598
1514	hidnplayr	1599	cmp esi, -1
		1600	jne .not_minus_one
1159	hidnplayr	1601
1514	hidnplayr	1602	; If FIN has been set, but not ACKed, and we havent been called to retransmit,
		1603	; len (esi) will be -1
		1604	; Otherwise, window shrank after we sent into it.
		1605	; If window shrank to 0, cancel pending retransmit and pull SND_NXT back to (closed) window
		1606	; We will enter persist state below.
		1607	; If window didn't close completely, just wait for an ACK
1159	hidnplayr	1608
1514	hidnplayr	1609	xor esi, esi
1159	hidnplayr	1610
1514	hidnplayr	1611	test ecx, ecx
		1612	jnz @f
1159	hidnplayr	1613
1529	hidnplayr	1614	mov [eax + TCP_SOCKET.timer_retransmission], 0 ; cancel retransmit
1274	hidnplayr	1615
1514	hidnplayr	1616	push [eax + TCP_SOCKET.SND_UNA]
		1617	pop [eax + TCP_SOCKET.SND_NXT]
		1618	@@:
1254	hidnplayr	1619
1514	hidnplayr	1620	.not_minus_one:
1254	hidnplayr	1621
1514	hidnplayr	1622	;;; 124
1159	hidnplayr	1623
1514	hidnplayr	1624	cmp esi, [eax + TCP_SOCKET.t_maxseg]
		1625	jle @f
1274	hidnplayr	1626
1514	hidnplayr	1627	mov esi, [eax + TCP_SOCKET.t_maxseg]
		1628	;sendalot = 1
1274	hidnplayr	1629
1514	hidnplayr	1630	@@:
1274	hidnplayr	1631
1514	hidnplayr	1632	;;; 128
1274	hidnplayr	1633
1514	hidnplayr	1634	mov edi, [eax + TCP_SOCKET.SND_NXT]
		1635	add edi, esi ; len
		1636	sub edi, [eax + TCP_SOCKET.SND_UNA]
1533	hidnplayr	1637	add edi, [eax + STREAM_SOCKET.snd + RING_BUFFER.size]
1514	hidnplayr	1638	cmp edi, 0
		1639	jle @f
1274	hidnplayr	1640
1514	hidnplayr	1641	and dl, not (TH_FIN) ; clear the FIN flag
1159	hidnplayr	1642
1514	hidnplayr	1643	@@:
1159	hidnplayr	1644
		1645
1529	hidnplayr	1646	; set ecx to space available in receive buffer
		1647	; From now on, ecx will be the window we advertise to the other end
1159	hidnplayr	1648
1529	hidnplayr	1649	mov ecx, SOCKET_MAXDATA
1533	hidnplayr	1650	sub ecx, [eax + STREAM_SOCKET.rcv + RING_BUFFER.size]
1159	hidnplayr	1651
1514	hidnplayr	1652	;------------------------------
		1653	; Sender silly window avoidance
1159	hidnplayr	1654
1529	hidnplayr	1655	cmp ecx, [eax + TCP_SOCKET.t_maxseg]
1514	hidnplayr	1656	je .send
1274	hidnplayr	1657
1514	hidnplayr	1658	;;; TODO: 144-145
1274	hidnplayr	1659
1514	hidnplayr	1660	test [eax + TCP_SOCKET.t_force], -1
		1661	jnz .send
1274	hidnplayr	1662
1529	hidnplayr	1663	mov ebx, [eax + TCP_SOCKET.max_sndwnd]
		1664	shr ebx, 1
		1665	cmp ecx, ebx
		1666	jge .send
1274	hidnplayr	1667
1529	hidnplayr	1668	mov ebx, [eax + TCP_SOCKET.SND_NXT]
		1669	cmp ebx, [eax + TCP_SOCKET.SND_MAX]
		1670	jl .send
1254	hidnplayr	1671
1514	hidnplayr	1672	;----------------------------------------
		1673	; Check if a window update should be sent
1159	hidnplayr	1674
1529	hidnplayr	1675	test ecx, ecx ; window
		1676	jz .no_window
1159	hidnplayr	1677
1514	hidnplayr	1678	;;; TODO 154-172
1159	hidnplayr	1679
1514	hidnplayr	1680	.no_window:
1159	hidnplayr	1681
1514	hidnplayr	1682	;--------------------------
		1683	; Should a segment be sent?
1159	hidnplayr	1684
1534	hidnplayr	1685	test [eax + TCP_SOCKET.t_flags], TF_ACKNOW
1514	hidnplayr	1686	jnz .send
1159	hidnplayr	1687
1514	hidnplayr	1688	test dl, TH_SYN + TH_RST
		1689	jnz .send
1159	hidnplayr	1690
1534	hidnplayr	1691	mov ebx, [eax + TCP_SOCKET.SND_UP]
		1692	cmp ebx, [eax + TCP_SOCKET.SND_UNA]
1514	hidnplayr	1693	jg .send
1249	hidnplayr	1694
1514	hidnplayr	1695	test dl, TH_FIN
		1696	jz .enter_persist
1318	hidnplayr	1697
1534	hidnplayr	1698	test [eax + TCP_SOCKET.t_flags], TF_SENTFIN
1514	hidnplayr	1699	jnz .send
1254	hidnplayr	1700
1534	hidnplayr	1701	mov ebx, [eax + TCP_SOCKET.SND_NXT]
		1702	cmp ebx, [eax + TCP_SOCKET.SND_UNA]
1514	hidnplayr	1703	je .send
1254	hidnplayr	1704
1514	hidnplayr	1705	;--------------------
		1706	; Enter persist state
1318	hidnplayr	1707
1514	hidnplayr	1708	.enter_persist:
1318	hidnplayr	1709
1519	hidnplayr	1710	DEBUGF 1,"Entering persist state\n"
1318	hidnplayr	1711
1514	hidnplayr	1712	;--------------------------------------
		1713	; No reason to send a segment, just ret
1318	hidnplayr	1714
1514	hidnplayr	1715	DEBUGF 1,"No reason to send a segment\n"
1318	hidnplayr	1716
1514	hidnplayr	1717	ret
1318	hidnplayr	1718
		1719
1514	hidnplayr	1720	;-----------------------------------------------
		1721	;
		1722	; Send a segment
		1723	;
1529	hidnplayr	1724	; eax = socket pointer
1514	hidnplayr	1725	; dl = flags
		1726	;
		1727	;-----------------------------------------------
1318	hidnplayr	1728
1529	hidnplayr	1729	.send:
1318	hidnplayr	1730
1514	hidnplayr	1731	DEBUGF 1,"Preparing to send a segment\n"
1318	hidnplayr	1732
1529	hidnplayr	1733	mov edi, TCP_segment.Data ; edi will contain headersize
1318	hidnplayr	1734
1529	hidnplayr	1735	sub esp, 8 ; create some space on stack
		1736	push eax ; save this too..
		1737
1514	hidnplayr	1738	;------------------------------------
		1739	; Send options with first SYN segment
1318	hidnplayr	1740
1514	hidnplayr	1741	test dl, TH_SYN
		1742	jz .no_options
1318	hidnplayr	1743
1529	hidnplayr	1744	push [eax + TCP_SOCKET.ISS]
		1745	pop [eax + TCP_SOCKET.SND_NXT]
1318	hidnplayr	1746
1529	hidnplayr	1747	test [eax + TCP_SOCKET.t_flags], TF_NOOPT
1514	hidnplayr	1748	jnz .no_options
1318	hidnplayr	1749
1529	hidnplayr	1750	mov ecx, 1460
		1751	or ecx, TCP_OPT_MAXSEG shl 24 + 4 shl 16
		1752	bswap ecx
		1753	push ecx
		1754	add di, 4
1514	hidnplayr	1755
1529	hidnplayr	1756	test [eax + TCP_SOCKET.t_flags], TF_REQ_SCALE
1514	hidnplayr	1757	jz .no_syn
		1758
		1759	test dl, TH_ACK
		1760	jnz .scale_opt
		1761
1529	hidnplayr	1762	test [eax + TCP_SOCKET.t_flags], TF_RCVD_SCALE
1514	hidnplayr	1763	jz .no_syn
		1764
		1765	.scale_opt:
1529	hidnplayr	1766	movzx ecx, byte [eax + TCP_SOCKET.request_r_scale]
		1767	or ecx, TCP_OPT_WINDOW shl 24 + 4 shl 16 + TCP_OPT_NOP shl 8
		1768	bswap ecx
		1769	pushd ecx
1514	hidnplayr	1770	add di, 4
1159	hidnplayr	1771
1514	hidnplayr	1772	.no_syn:
1159	hidnplayr	1773
1514	hidnplayr	1774	;------------------------------------
		1775	; Make the timestamp option if needed
1159	hidnplayr	1776
1529	hidnplayr	1777	test [eax + TCP_SOCKET.t_flags], TF_REQ_TSTMP
1514	hidnplayr	1778	jz .no_timestamp
1159	hidnplayr	1779
1514	hidnplayr	1780	test dl, TH_RST
		1781	jnz .no_timestamp
		1782
		1783	test dl, TH_ACK
		1784	jz .timestamp
		1785
1529	hidnplayr	1786	test [eax + TCP_SOCKET.t_flags], TF_RCVD_TSTMP
1514	hidnplayr	1787	jz .no_timestamp
		1788
		1789	.timestamp:
1529	hidnplayr	1790	mov esi, [timer_ticks]
		1791	bswap esi
		1792	push esi
1514	hidnplayr	1793	pushw 0
1529	hidnplayr	1794	pushd TCP_OPT_TIMESTAMP + 10 shl 8 + TCP_OPT_NOP shl 16 + TCP_OPT_NOP shl 24
1514	hidnplayr	1795	add di, 10
		1796
		1797	.no_timestamp:
		1798	;; TODO: check if we dont exceed the max segment size
		1799
		1800	.no_options:
1529	hidnplayr	1801	; eax = socket ptr
		1802	; edx = flags
		1803	; ecx = data size
		1804	; edi = header size
		1805	; esi = snd ring buff ptr
1514	hidnplayr	1806
1533	hidnplayr	1807	mov ecx, [eax + STREAM_SOCKET.snd + RING_BUFFER.size]
		1808	cmp ecx, [eax + TCP_SOCKET.t_maxseg] ;;; right?
		1809	jle @f
		1810	mov ecx, [eax + TCP_SOCKET.t_maxseg]
		1811	@@:
1514	hidnplayr	1812	add ecx, edi ; total TCP segment size
		1813
1529	hidnplayr	1814	; Start by pushing all TCP header values in reverse order on stack
		1815	; (essentially, creating the tcp header!)
1514	hidnplayr	1816
1529	hidnplayr	1817	pushw 0 ; .UrgentPointer dw ?
		1818	pushw 0 ; .Checksum dw ?
		1819	pushw 0x00a0 ; .Window dw ? ;;;;;;;
		1820	shl edi, 2 ; .DataOffset db ? only 4 left-most bits
		1821	shl dx, 8
		1822	or dx, di ; .Flags db ?
		1823	pushw dx
		1824	shr edi, 2 ; .DataOffset db ? ;;;;
1514	hidnplayr	1825
1529	hidnplayr	1826	push [eax + TCP_SOCKET.RCV_NXT] ; .AckNumber dd ?
1543	hidnplayr	1827	ntohd [esp]
1159	hidnplayr	1828
1529	hidnplayr	1829	push [eax + TCP_SOCKET.SND_NXT] ; .SequenceNumber dd ?
1543	hidnplayr	1830	ntohd [esp]
1159	hidnplayr	1831
1529	hidnplayr	1832	push [eax + TCP_SOCKET.RemotePort] ; .DestinationPort dw ?
1543	hidnplayr	1833	ntohw [esp]
1249	hidnplayr	1834
1529	hidnplayr	1835	push [eax + TCP_SOCKET.LocalPort] ; .SourcePort dw ?
1543	hidnplayr	1836	ntohw [esp]
1274	hidnplayr	1837
1533	hidnplayr	1838	push edi ; header size
1274	hidnplayr	1839
1529	hidnplayr	1840	; Create the IP packet
		1841	mov ebx, [eax + IP_SOCKET.LocalIP] ; source ip
		1842	mov eax, [eax + IP_SOCKET.RemoteIP] ; dest ip
		1843	mov di, IP_PROTO_TCP shl 8 + 128
		1844	call IPv4_output
		1845	jz .fail
1274	hidnplayr	1846
1529	hidnplayr	1847	;-----------------------------------------
		1848	; Move TCP header from stack to TCP packet
1274	hidnplayr	1849
1533	hidnplayr	1850	push ecx
		1851	mov ecx, [esp+4]
		1852	lea esi, [esp+4+4]
1529	hidnplayr	1853	shr ecx, 2
		1854	rep movsd
1533	hidnplayr	1855	pop ecx ; full TCP packet size
1274	hidnplayr	1856
1533	hidnplayr	1857	pop esi ; headersize
		1858	add esp, esi
1254	hidnplayr	1859
1533	hidnplayr	1860	mov [esp + 4], eax ; packet ptr
1530	hidnplayr	1861	mov [esp + 4+4], edx ; packet size
1254	hidnplayr	1862
1533	hidnplayr	1863	mov edx, edi ; begin of data
		1864	sub edx, esi ; begin of packet (edi = begin of data)
		1865	push ecx
		1866	sub ecx, esi ; data size
1159	hidnplayr	1867
1514	hidnplayr	1868	;--------------
		1869	; Copy the data
1159	hidnplayr	1870
1529	hidnplayr	1871	; eax = ptr to ring struct
		1872	; ecx = buffer size
		1873	; edi = ptr to buffer
1249	hidnplayr	1874
1536	hidnplayr	1875	; test ecx, ecx
1533	hidnplayr	1876	mov eax, [esp+4] ; socket ptr
1536	hidnplayr	1877	add [eax + TCP_SOCKET.SND_NXT], ecx
		1878	add eax, STREAM_SOCKET.snd
1533	hidnplayr	1879	push edx
1529	hidnplayr	1880	call SOCKET_ring_read
1536	hidnplayr	1881	pop esi
		1882	pop ecx
1529	hidnplayr	1883	pop eax
1254	hidnplayr	1884
1533	hidnplayr	1885	test [esi + TCP_segment.Flags], TH_SYN + TH_FIN
		1886	jz @f
		1887	inc [eax + TCP_SOCKET.SND_NXT]
		1888	;;; TODO: update sentfin flag
		1889	@@:
1254	hidnplayr	1890
1533	hidnplayr	1891	mov edx, [eax + TCP_SOCKET.SND_NXT]
		1892	cmp edx, [eax + TCP_SOCKET.SND_MAX]
		1893	jle @f
		1894	mov [eax + TCP_SOCKET.SND_MAX], edx
		1895
		1896	;;;; TODO: time transmission (420)
		1897	@@:
		1898
		1899	;;; TODO: set retransmission timer
		1900
		1901	;--------------------
		1902	; Create the checksum
		1903
1529	hidnplayr	1904	DEBUGF 1,"checksum: ptr=%x size=%u\n", esi, ecx
1159	hidnplayr	1905
1529	hidnplayr	1906	TCP_checksum (eax + IP_SOCKET.LocalIP), (eax + IP_SOCKET.RemoteIP)
		1907	mov [esi+TCP_segment.Checksum], dx
		1908
1514	hidnplayr	1909	;----------------
		1910	; Send the packet
1159	hidnplayr	1911
1529	hidnplayr	1912	DEBUGF 1,"Sending TCP Packet to device %x\n", ebx
		1913	call [ebx + NET_DEVICE.transmit]
		1914	ret
1159	hidnplayr	1915
1514	hidnplayr	1916
1529	hidnplayr	1917	.fail:
		1918	pop ecx
		1919	add esp, ecx
1536	hidnplayr	1920	add esp, 4+8
1529	hidnplayr	1921	DEBUGF 1,"TCP_output: failed\n"
1159	hidnplayr	1922	ret
		1923
1529	hidnplayr	1924
		1925
1514	hidnplayr	1926	;-------------------------
		1927	;
		1928	; TCP_outflags
		1929	;
		1930	; IN: eax = socket ptr
		1931	;
		1932	; OUT: edx = flags
		1933	;
		1934	;-------------------------
1249	hidnplayr	1935	align 4
1514	hidnplayr	1936	TCP_outflags:
1254	hidnplayr	1937
1514	hidnplayr	1938	mov edx, [eax + TCP_SOCKET.t_state]
		1939	movzx edx, byte [edx + .flaglist]
1254	hidnplayr	1940
1514	hidnplayr	1941	DEBUGF 1,"TCP_outflags, socket: %x, flags: %x\n", eax, dl
		1942
1159	hidnplayr	1943	ret
		1944
1514	hidnplayr	1945	.flaglist:
1159	hidnplayr	1946
1514	hidnplayr	1947	db TH_RST + TH_ACK ; TCB_CLOSED
		1948	db 0 ; TCB_LISTEN
		1949	db TH_SYN ; TCB_SYN_SENT
		1950	db TH_SYN + TH_ACK ; TCB_SYN_RECEIVED
		1951	db TH_ACK ; TCB_ESTABLISHED
		1952	db TH_ACK ; TCB_CLOSE_WAIT
		1953	db TH_SYN + TH_ACK ; TCB_FIN_WAIT_1
		1954	db TH_SYN + TH_ACK ; TCB_CLOSING
		1955	db TH_SYN + TH_ACK ; TCB_LAST_ACK
		1956	db TH_ACK ; TCB_FIN_WAIT_2
		1957	db TH_ACK ; TCB_TIMED_WAIT
1249	hidnplayr	1958
1514	hidnplayr	1959
1529	hidnplayr	1960
		1961
1514	hidnplayr	1962	;-------------------------
		1963	;
		1964	; TCP_drop
		1965	;
		1966	; IN: eax = socket ptr
		1967	;
		1968	; OUT: /
		1969	;
		1970	;-------------------------
1249	hidnplayr	1971	align 4
1514	hidnplayr	1972	TCP_drop:
1254	hidnplayr	1973
1514	hidnplayr	1974	DEBUGF 1,"TCP_drop\n"
1254	hidnplayr	1975
1514	hidnplayr	1976	; cmp [eax + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		1977	; jl .no_syn_received
1159	hidnplayr	1978
1514	hidnplayr	1979	mov [eax + TCP_SOCKET.t_state], TCB_CLOSED
1159	hidnplayr	1980
1514	hidnplayr	1981	call TCP_output
1254	hidnplayr	1982
1514	hidnplayr	1983	; .no_syn_received:
		1984
1159	hidnplayr	1985	ret
		1986
		1987
1254	hidnplayr	1988
		1989
1159	hidnplayr	1990
1514	hidnplayr	1991	;---------------------------------------
		1992	;
1519	hidnplayr	1993	; The easy way to send an ACK/RST/keepalive segment
1514	hidnplayr	1994	;
1529	hidnplayr	1995	; TCP_respond_socket:
		1996	;
		1997	; IN: ebx = socket ptr
1519	hidnplayr	1998	; cl = flags
1514	hidnplayr	1999	;
1529	hidnplayr	2000	;--------------------------------------
1514	hidnplayr	2001	align 4
1529	hidnplayr	2002	TCP_respond_socket:
1254	hidnplayr	2003
1529	hidnplayr	2004	DEBUGF 1,"TCP_respond_socket\n"
1159	hidnplayr	2005
1519	hidnplayr	2006	;---------------------
		2007	; Create the IP packet
		2008
1529	hidnplayr	2009	push cx ebx
		2010	mov eax, [ebx + IP_SOCKET.RemoteIP]
		2011	mov ebx, [ebx + IP_SOCKET.LocalIP]
1519	hidnplayr	2012	mov ecx, TCP_segment.Data
1529	hidnplayr	2013	mov di , IP_PROTO_TCP shl 8 + 128
		2014	call IPv4_output
1519	hidnplayr	2015	test edi, edi
		2016	jz .error
1529	hidnplayr	2017	pop esi cx
		2018	push edx eax
1519	hidnplayr	2019
1529	hidnplayr	2020	;-----------------------------------------------
		2021	; Fill in the TCP header by using the socket ptr
1519	hidnplayr	2022
1529	hidnplayr	2023	mov ax, [esi + TCP_SOCKET.LocalPort]
		2024	rol ax, 8
		2025	stosw
		2026	mov ax, [esi + TCP_SOCKET.RemotePort]
		2027	rol ax, 8
		2028	stosw
		2029	mov eax, [esi + TCP_SOCKET.SND_NXT]
		2030	bswap eax
		2031	stosd
		2032	mov eax, [esi + TCP_SOCKET.RCV_NXT]
		2033	bswap eax
		2034	stosd
		2035	mov al, 0x50 ; Dataoffset: 20 bytes
		2036	stosb
		2037	mov al, cl
		2038	stosb
		2039	mov ax, [esi + TCP_SOCKET.RCV_WND]
		2040	rol ax, 8
		2041	stosw ; window
		2042	xor eax, eax
		2043	stosd ; checksum + urgentpointer
1519	hidnplayr	2044
		2045	;---------------------
		2046	; Fill in the checksum
		2047
		2048	.checksum:
1529	hidnplayr	2049	sub edi, TCP_segment.Data
		2050	mov ecx, TCP_segment.Data
		2051	xchg esi, edi
		2052	TCP_checksum (edi + IP_SOCKET.LocalIP), (esi + IP_SOCKET.RemoteIP)
		2053	mov [esi+TCP_segment.Checksum], dx
1519	hidnplayr	2054
		2055	;--------------------
		2056	; And send the segment
		2057
		2058	call [ebx + NET_DEVICE.transmit]
1159	hidnplayr	2059	ret
		2060
1519	hidnplayr	2061	.error:
1529	hidnplayr	2062	DEBUGF 1,"TCP_respond failed\n"
		2063	add esp, 2+4
1159	hidnplayr	2064
1519	hidnplayr	2065	ret
1514	hidnplayr	2066
1529	hidnplayr	2067
		2068
		2069	;-------------------------
		2070	; TCP_respond.segment:
		2071	;
		2072	; IN: edx = segment ptr (a previously received segment)
		2073	; cl = flags
		2074
		2075	align 4
		2076	TCP_respond_segment:
		2077
		2078	DEBUGF 1,"TCP_respond_segment\n"
		2079
		2080	;---------------------
		2081	; Create the IP packet
		2082
		2083	push cx edx
		2084	mov ebx, [edx - 20 + IPv4_Packet.SourceAddress] ;;;; and what if ip packet had options?!
		2085	mov eax, [edx - 20 + IPv4_Packet.DestinationAddress] ;;;
		2086	mov ecx, TCP_segment.Data
		2087	mov di , IP_PROTO_TCP shl 8 + 128
		2088	call IPv4_output
		2089	jz .error
1533	hidnplayr	2090	pop esi cx
1529	hidnplayr	2091
		2092	push edx eax
		2093
1519	hidnplayr	2094	;---------------------------------------------------
		2095	; Fill in the TCP header by using a received segment
		2096
		2097	mov ax, [esi + TCP_segment.DestinationPort]
		2098	rol ax, 8
		2099	stosw
		2100	mov ax, [esi + TCP_segment.SourcePort]
		2101	rol ax, 8
		2102	stosw
		2103	mov eax, [esi + TCP_segment.AckNumber]
		2104	bswap eax
		2105	stosd
		2106	xor eax, eax
		2107	stosd
		2108	mov al, 0x50 ; Dataoffset: 20 bytes
		2109	stosb
		2110	mov al, cl
		2111	stosb
		2112	mov ax, 1280
		2113	rol ax, 8
		2114	stosw ; window
		2115	xor eax, eax
		2116	stosd ; checksum + urgentpointer
		2117
1529	hidnplayr	2118	;---------------------
		2119	; Fill in the checksum
1519	hidnplayr	2120
1529	hidnplayr	2121	.checksum:
		2122	lea esi, [edi - TCP_segment.Data]
		2123	mov ecx, TCP_segment.Data
		2124	TCP_checksum (esi - 20 + IPv4_Packet.DestinationAddress), (esi - 20 + IPv4_Packet.DestinationAddress)
		2125	mov [esi+TCP_segment.Checksum], dx
1519	hidnplayr	2126
1529	hidnplayr	2127	;--------------------
		2128	; And send the segment
1519	hidnplayr	2129
1529	hidnplayr	2130	call [ebx + NET_DEVICE.transmit]
		2131	ret
1519	hidnplayr	2132
1529	hidnplayr	2133	.error:
		2134	DEBUGF 1,"TCP_respond failed\n"
		2135	add esp, 2+4
1519	hidnplayr	2136
		2137	ret
		2138
		2139
		2140
1254	hidnplayr	2141
		2142	;---------------------------------------------------------------------------
		2143	;
		2144	; TCP_API
		2145	;
		2146	; This function is called by system function 75
		2147	;
		2148	; IN: subfunction number in bl
		2149	; device number in bh
		2150	; ecx, edx, .. depends on subfunction
		2151	;
		2152	; OUT:
		2153	;
		2154	;---------------------------------------------------------------------------
		2155	align 4
		2156	TCP_API:
		2157
		2158	movzx eax, bh
		2159	shl eax, 2
		2160
		2161	test bl, bl
		2162	jz .packets_tx ; 0
		2163	dec bl
		2164	jz .packets_rx ; 1
		2165
		2166	.error:
		2167	mov eax, -1
		2168	ret
		2169
		2170	.packets_tx:
1514	hidnplayr	2171	add eax, TCP_segments_tx
1254	hidnplayr	2172	mov eax, [eax]
		2173	ret
		2174
		2175	.packets_rx:
1514	hidnplayr	2176	add eax, TCP_segments_rx
1254	hidnplayr	2177	mov eax, [eax]
		2178	ret

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(root)/kernel/branches/net/network/tcp.inc – Rev 1543