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: 1719 $
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
1719	hidnplayr	575	DEBUGF 1,"TCP_segment.window=%u\n", [edx + TCP_segment.Window]:4
		576	DEBUGF 1,"TCP_SOCKET.SND_WND=%u\n", [ebx + TCP_SOCKET.SND_WND]:4
1543	hidnplayr	577	mov eax, dword [edx + TCP_segment.Window]
1536	hidnplayr	578	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		579	jne .not_uni_xfer
1514	hidnplayr	580
		581	mov eax, [ebx + TCP_SOCKET.SND_NXT]
		582	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		583	jne .not_uni_xfer
		584
		585	;---------------------------------------
		586	; check if we are sender in the uni-xfer
		587
		588	; If the following 4 conditions are all true, this segment is a pure ACK.
		589	;
1529	hidnplayr	590	; - The segment contains no data.
		591	test ecx, ecx
1514	hidnplayr	592	jnz .not_sender
1274	hidnplayr	593
1529	hidnplayr	594	; - The congestion window is greater than or equal to the current send window.
1514	hidnplayr	595	; 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.
		596	mov eax, [ebx + TCP_SOCKET.SND_CWND]
		597	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		598	jl .not_uni_xfer
1318	hidnplayr	599
1529	hidnplayr	600	; - The acknowledgment field in the segment is less than or equal to the maximum sequence number sent.
1534	hidnplayr	601	mov eax, [edx + TCP_segment.AckNumber]
		602	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
1529	hidnplayr	603	jg .not_uni_xfer
		604
		605	; - The acknowledgment field in the segment is greater than the largest unacknowledged sequence number.
1534	hidnplayr	606	sub eax, [ebx + TCP_SOCKET.SND_UNA]
1529	hidnplayr	607	jle .not_uni_xfer
		608
1514	hidnplayr	609	DEBUGF 1,"Header prediction: we are sender\n"
1274	hidnplayr	610
1514	hidnplayr	611	;---------------------------------
		612	; Packet is a pure ACK, process it
1274	hidnplayr	613
1514	hidnplayr	614	; Update RTT estimators
1159	hidnplayr	615
1514	hidnplayr	616	; Delete acknowledged bytes from send buffer
1719	hidnplayr	617	pusha
1536	hidnplayr	618	mov ecx, eax
1533	hidnplayr	619	lea eax, [ebx + STREAM_SOCKET.snd]
1529	hidnplayr	620	call SOCKET_ring_free
1719	hidnplayr	621	popa
1529	hidnplayr	622
1536	hidnplayr	623	; update window pointers
		624	mov eax, [edx + TCP_segment.AckNumber]
		625	dec eax
		626	mov [ebx + TCP_SOCKET.SND_WL1], eax
		627
1514	hidnplayr	628	; Stop retransmit timer
1519	hidnplayr	629	mov [ebx + TCP_SOCKET.timer_ack], 0
1159	hidnplayr	630
1514	hidnplayr	631	; Awaken waiting processes
1519	hidnplayr	632	mov eax, ebx
		633	call SOCKET_notify_owner
1318	hidnplayr	634
1719	hidnplayr	635	;; Generate more output FIXME
1536	hidnplayr	636	;; mov eax, ebx
		637	;; call TCP_output
		638	;;
		639	;; jmp .drop
1719	hidnplayr	640	jmp .ack_processed
1254	hidnplayr	641
1514	hidnplayr	642	;-------------------------------------------------
		643	; maybe we are the receiver in the uni-xfer then..
		644
		645	.not_sender:
1529	hidnplayr	646	; - The amount of data in the segment is greater than 0 (data count is in ecx)
1514	hidnplayr	647
1529	hidnplayr	648	; - The acknowledgment field equals the largest unacknowledged sequence number. This means no data is acknowledged by this segment.
1514	hidnplayr	649	mov eax, [edx + TCP_segment.AckNumber]
		650	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
		651	jne .not_uni_xfer
		652
1719	hidnplayr	653	; - The reassembly list of out-of-order segments for the connection is empty (seg_next equals tp).
1514	hidnplayr	654
1719	hidnplayr	655	;;;;;;; TODO
		656
1514	hidnplayr	657	jnz .not_uni_xfer
		658
		659	;-------------------------------------
		660	; Complete processing of received data
		661
		662	DEBUGF 1,"header prediction: we are receiver\nreceiving %u bytes of data\n", ecx
		663
1719	hidnplayr	664	pusha
1529	hidnplayr	665	add esi, edx
1533	hidnplayr	666	lea eax, [ebx + STREAM_SOCKET.rcv]
		667	call SOCKET_ring_write ; Add the data to the socket buffer
1514	hidnplayr	668
1533	hidnplayr	669	mov eax, ebx
		670	call SOCKET_notify_owner
1719	hidnplayr	671	popa
1533	hidnplayr	672
1529	hidnplayr	673	add [ebx + TCP_SOCKET.RCV_NXT], ecx ; Update sequence number with number of bytes we have copied
		674	or [ebx + TCP_SOCKET.t_flags], TF_DELACK ; Set delayed ack flag
1514	hidnplayr	675
		676	jmp .drop
		677
		678	;----------------------------------------------------
1529	hidnplayr	679	; Header prediction failed, doing it the slow way.. ;;;;; current implementation of header prediction destroys some regs (ecx) !!
1514	hidnplayr	680
		681	.not_uni_xfer:
		682
1533	hidnplayr	683	DEBUGF 1,"Header prediction failed\n" ; time to do it the "slow" way :)
1514	hidnplayr	684
		685	;------------------------------
		686	; Calculate receive window size
		687
		688	;;;;
		689
1529	hidnplayr	690	cmp [ebx + TCP_SOCKET.t_state], TCB_LISTEN
1514	hidnplayr	691	je .LISTEN
		692
1529	hidnplayr	693	cmp [ebx + TCP_SOCKET.t_state], TCB_SYN_SENT
1514	hidnplayr	694	je .SYN_SENT
		695
		696	;--------------------------------------------
		697	; Protection Against Wrapped Sequence Numbers
		698
1533	hidnplayr	699	; First, check if timestamp is present
1514	hidnplayr	700
		701	;;;; TODO
		702
		703	; Then, check if at least some bytes of data are within window
		704
		705	;;;; TODO
		706
		707	jmp .trim_then_step6
		708
1529	hidnplayr	709	;-------------
		710	; Passive Open
		711
1249	hidnplayr	712	align 4
1514	hidnplayr	713	.LISTEN:
1196	hidnplayr	714
1514	hidnplayr	715	DEBUGF 1,"TCP state: listen\n"
1159	hidnplayr	716
1543	hidnplayr	717	test [edx + TCP_segment.Flags], TH_RST ;;; TODO: kill new socket on error
1514	hidnplayr	718	jnz .drop
1159	hidnplayr	719
1514	hidnplayr	720	test [edx + TCP_segment.Flags], TH_ACK
		721	jnz .drop_with_reset
1159	hidnplayr	722
1514	hidnplayr	723	test [edx + TCP_segment.Flags], TH_SYN
		724	jz .drop
1159	hidnplayr	725
1533	hidnplayr	726
1514	hidnplayr	727	; TODO: check if it's a broadcast or multicast, and drop if so
1159	hidnplayr	728
1529	hidnplayr	729	;-----------------------
		730	; Fill in some variables
1514	hidnplayr	731
1529	hidnplayr	732	add [TCP_sequence_num], 64000
1514	hidnplayr	733
1529	hidnplayr	734	push [edx + TCP_segment.SourcePort]
		735	pop [eax + TCP_SOCKET.RemotePort]
1514	hidnplayr	736
1529	hidnplayr	737	push [edx + TCP_segment.SequenceNumber]
		738	pop [eax + TCP_SOCKET.IRS]
1159	hidnplayr	739
1529	hidnplayr	740	push [eax + TCP_SOCKET.ISS]
		741	pop [eax + TCP_SOCKET.SND_NXT]
1159	hidnplayr	742
1543	hidnplayr	743	TCP_sendseqinit eax
		744	TCP_rcvseqinit eax
		745
1529	hidnplayr	746	mov [eax + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		747	mov [eax + TCP_SOCKET.t_flags], TF_ACKNOW
1543	hidnplayr	748	mov [eax + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval ;;;; macro
1159	hidnplayr	749
1543	hidnplayr	750	add eax, STREAM_SOCKET.snd
		751	call SOCKET_ring_create
		752
		753	add eax, STREAM_SOCKET.rcv - STREAM_SOCKET.snd
		754	call SOCKET_ring_create
		755
		756	sub eax, STREAM_SOCKET.rcv
		757
		758	mov [eax + SOCKET.lock], 0
		759	mov ebx, eax ; if there is data, it must arrive in this new socket!
1514	hidnplayr	760	jmp .trim_then_step6
1159	hidnplayr	761
1254	hidnplayr	762
1529	hidnplayr	763	;------------
		764	; Active Open
1159	hidnplayr	765
1514	hidnplayr	766	align 4
		767	.SYN_SENT:
1281	hidnplayr	768
1514	hidnplayr	769	DEBUGF 1,"TCP state: syn_sent\n"
1159	hidnplayr	770
1514	hidnplayr	771	test [edx + TCP_segment.Flags], TH_ACK
		772	jz @f
1281	hidnplayr	773
1514	hidnplayr	774	mov eax, [edx + TCP_segment.AckNumber]
		775	cmp eax, [ebx + TCP_SOCKET.ISS]
		776	jle .drop_with_reset
1533	hidnplayr	777	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		778	jg .drop_with_reset
1514	hidnplayr	779	@@:
1281	hidnplayr	780
1514	hidnplayr	781	test [edx + TCP_segment.Flags], TH_RST
		782	jz @f
1281	hidnplayr	783
1514	hidnplayr	784	test [edx + TCP_segment.Flags], TH_ACK
		785	jz .drop
1281	hidnplayr	786
1719	hidnplayr	787	mov eax, ebx
1716	hidnplayr	788	mov ebx, ECONNREFUSED
		789	call TCP_drop
1159	hidnplayr	790
1514	hidnplayr	791	jmp .drop
		792	@@:
1159	hidnplayr	793
1514	hidnplayr	794	test [edx + TCP_segment.Flags], TH_SYN
		795	jz .drop
1318	hidnplayr	796
1529	hidnplayr	797	; at this point, segment seems to be valid
		798
1514	hidnplayr	799	test [edx + TCP_segment.Flags], TH_ACK
1529	hidnplayr	800	jz .no_syn_ack
1514	hidnplayr	801
1529	hidnplayr	802	; now, process received SYN in response to an active open
		803
1514	hidnplayr	804	mov eax, [edx + TCP_segment.AckNumber]
		805	mov [ebx + TCP_SOCKET.SND_UNA], eax
		806	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		807	jle @f
		808	mov [ebx + TCP_SOCKET.SND_NXT], eax
1529	hidnplayr	809	@@:
1514	hidnplayr	810
1529	hidnplayr	811	.no_syn_ack:
1514	hidnplayr	812
1529	hidnplayr	813	mov [ebx + TCP_SOCKET.timer_retransmission], 0 ; disable retransmission
1514	hidnplayr	814
1529	hidnplayr	815	push [edx + TCP_segment.SequenceNumber]
		816	pop [ebx + TCP_SOCKET.IRS]
		817
1533	hidnplayr	818	TCP_rcvseqinit ebx
1529	hidnplayr	819
		820	mov [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
		821
		822	mov eax, [ebx + TCP_SOCKET.SND_UNA]
		823	cmp eax, [ebx + TCP_SOCKET.ISS]
		824	jle .simultaneous_open
		825
		826	test [edx + TCP_segment.Flags], TH_ACK
		827	jz .simultaneous_open
		828
		829	DEBUGF 1,"TCP: active open\n"
		830
		831	; TODO: update stats
1533	hidnplayr	832	; TODO: set general socket state to connected
1514	hidnplayr	833
		834	mov [ebx + TCP_SOCKET.t_state], TCB_ESTABLISHED
		835
		836	; TODO: check if we should scale the connection (567-572)
		837	; TODO: update RTT estimators
		838
1529	hidnplayr	839	jmp .trimthenstep6
1514	hidnplayr	840
1529	hidnplayr	841	.simultaneous_open:
1514	hidnplayr	842
1529	hidnplayr	843	DEBUGF 1,"TCP: simultaneous open\n"
1514	hidnplayr	844	; We have received a syn but no ACK, so we are having a simultaneous open..
		845	mov [ebx + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		846
		847	;-------------------------------------
		848	; Common processing for receipt of SYN
		849
		850	.trimthenstep6:
		851
		852	inc [edx + TCP_segment.SequenceNumber]
		853
		854	cmp cx, [ebx + TCP_SOCKET.RCV_WND]
		855	jle @f
		856
		857	movzx eax, cx
		858	sub ax, [ebx + TCP_SOCKET.RCV_WND]
		859	; TODO: 592
		860	mov cx, [ebx + TCP_SOCKET.RCV_WND]
		861	; TODO...
		862	@@:
		863	;;;;;
1719	hidnplayr	864	jmp .ack_processed
1514	hidnplayr	865
		866
1529	hidnplayr	867	.trim_then_step6:
1159	hidnplayr	868
1514	hidnplayr	869	;----------------------------
		870	; trim any data not in window
1159	hidnplayr	871
1533	hidnplayr	872	DEBUGF 1,"Trimming window\n"
		873
1514	hidnplayr	874	mov eax, [ebx + TCP_SOCKET.RCV_NXT]
		875	sub eax, [edx + TCP_segment.SequenceNumber]
1533	hidnplayr	876	jz .no_duplicate
1274	hidnplayr	877
1514	hidnplayr	878	test [edx + TCP_segment.Flags], TH_SYN
		879	jz .no_drop
		880
		881	and [edx + TCP_segment.Flags], not (TH_SYN)
		882	inc [edx + TCP_segment.SequenceNumber]
		883
		884	cmp [edx + TCP_segment.UrgentPointer], 1
		885	jl @f
		886
		887	dec [edx + TCP_segment.UrgentPointer]
		888
		889	jmp .no_drop
		890	@@:
		891
		892	and [edx + TCP_segment.Flags], not (TH_URG)
		893	dec eax
1533	hidnplayr	894	jz .no_duplicate
1514	hidnplayr	895	.no_drop:
		896
1533	hidnplayr	897	DEBUGF 1,"Going to drop %u out of %u bytes\n", eax, ecx
1529	hidnplayr	898
1514	hidnplayr	899	; eax holds number of bytes to drop
		900
		901	;----------------------------------
		902	; Check for entire duplicate packet
		903
		904	cmp eax, ecx
		905	jge .duplicate
		906
		907	;;; TODO: figure 28.30
		908
		909	;------------------------
		910	; Check for duplicate FIN
		911
		912	test [edx + TCP_segment.Flags], TH_FIN
		913	jz @f
		914	inc ecx
		915	cmp eax, ecx
		916	dec ecx
		917	jne @f
		918
		919	mov eax, ecx
		920	and [edx + TCP_segment.Flags], not TH_FIN
1529	hidnplayr	921	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1514	hidnplayr	922	jmp .no_duplicate
		923	@@:
		924
		925	; Handle the case when a bound socket connects to itself
		926	; Allow packets with a SYN and an ACKto continue with the processing
		927
		928	;-------------------------------------
		929	; Generate duplicate ACK if nescessary
		930
		931	; This code also handles simultaneous half-open or self-connects
		932
		933	test eax, eax
		934	jnz .drop_after_ack
		935
		936	cmp [edx + TCP_segment.Flags], TH_ACK
		937	jz .drop_after_ack
		938
		939	.duplicate:
		940
1533	hidnplayr	941	DEBUGF 1,"Duplicate received\n"
1529	hidnplayr	942
1514	hidnplayr	943	;----------------------------------------
		944	; Update statistics for duplicate packets
		945
		946	;;; TODO
		947
1529	hidnplayr	948	jmp .drop ;;; DROP the packet ??
1514	hidnplayr	949
		950	.no_duplicate:
		951
		952	;-----------------------------------------------
		953	; Remove duplicate data and update urgent offset
		954
		955	add [edx + TCP_segment.SequenceNumber], eax
		956
		957	;;; TODO
		958
		959	sub [edx + TCP_segment.UrgentPointer], ax
		960	jg @f
		961
		962	and [edx + TCP_segment.Flags], not (TH_URG)
		963	mov [edx + TCP_segment.UrgentPointer], 0
		964	@@:
		965
		966	;--------------------------------------------------
		967	; Handle data that arrives after process terminates
		968
		969	cmp [ebx + SOCKET.PID], 0
1533	hidnplayr	970	jg @f
1514	hidnplayr	971
		972	cmp [ebx + TCP_SOCKET.t_state], TCB_CLOSE_WAIT
		973	jle @f
		974
		975	test ecx, ecx
		976	jz @f
		977
		978	;;; Close the socket
		979	;;; update stats
		980
		981	jmp .drop_with_reset
		982	@@:
		983
		984	;----------------------------------------
		985	; Remove data beyond right edge of window
		986
		987	mov eax, [edx + TCP_segment.SequenceNumber]
		988	add eax, ecx
		989	sub eax, [ebx + TCP_SOCKET.RCV_NXT]
		990	sub ax, [ebx + TCP_SOCKET.RCV_WND]
		991
		992	; eax now holds the number of bytes to drop
		993
		994	jle .no_excess_data
		995
		996	;;; TODO: update stats
		997
		998	cmp eax, ecx
		999	jl .dont_drop_all
		1000
		1001	;;; TODO 700-736
		1002
		1003	.dont_drop_all:
		1004
		1005	.no_excess_data:
		1006
		1007	;-----------------
		1008	; Record timestamp
		1009
		1010	;;; TODO 737-746
		1011
		1012	;------------------
		1013	; Process RST flags
		1014
		1015	test [edx + TCP_segment.Flags], TH_RST
		1016	jz .rst_skip
		1017
1529	hidnplayr	1018	DEBUGF 1,"Got an RST flag"
		1019
1514	hidnplayr	1020	mov eax, [ebx + TCP_SOCKET.t_state]
		1021	shl eax, 2
		1022	jmp dword [eax + .rst_sw_list]
		1023
		1024	.rst_sw_list:
		1025	dd .rst_skip ;TCB_CLOSED
		1026	dd .rst_skip ;TCB_LISTEN
		1027	dd .rst_skip ;TCB_SYN_SENT
		1028	dd .econnrefused ;TCB_SYN_RECEIVED
		1029	dd .econnreset ;TCB_ESTABLISHED
		1030	dd .econnreset ;TCB_CLOSE_WAIT
		1031	dd .econnreset ;TCB_FIN_WAIT_1
		1032	dd .rst_close ;TCB_CLOSING
		1033	dd .rst_close ;TCB_LAST_ACK
		1034	dd .econnreset ;TCB_FIN_WAIT_2
		1035	dd .rst_close ;TCB_TIMED_WAIT
		1036
		1037	.econnrefused:
		1038
1529	hidnplayr	1039	DEBUGF 1,"Connection refused"
		1040
1514	hidnplayr	1041	;;; TODO: debug info
		1042
		1043	jmp .close
		1044
		1045	.econnreset:
		1046
1529	hidnplayr	1047	DEBUGF 1,"Connection reset"
		1048
1514	hidnplayr	1049	;;; TODO: debug info
1529	hidnplayr	1050	.close:
1514	hidnplayr	1051
1529	hidnplayr	1052	DEBUGF 1,"Closing connection"
		1053
1514	hidnplayr	1054	;;; update stats
		1055
		1056	.rst_close:
		1057
1534	hidnplayr	1058	DEBUGF 1,"Closing with reset\n"
1529	hidnplayr	1059
1514	hidnplayr	1060	;;; Close the socket
		1061	jmp .drop
		1062
		1063	.rst_skip:
		1064
		1065	;--------------------------------------
		1066	; handle SYN-full and ACK-less segments
		1067
		1068	test [edx + TCP_segment.Flags], TH_SYN
		1069	jz @f
		1070
1719	hidnplayr	1071	mov eax, ebx
1716	hidnplayr	1072	mov ebx, ECONNRESET
		1073	call TCP_drop
		1074
1514	hidnplayr	1075	jmp .drop_with_reset
		1076
		1077	test [edx + TCP_segment.Flags], TH_ACK
		1078	jz .drop
1534	hidnplayr	1079	@@:
1514	hidnplayr	1080
1719	hidnplayr	1081	;---------------
		1082	; ACK processing
		1083
1514	hidnplayr	1084	cmp [ebx + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
1719	hidnplayr	1085	jnz .no_syn_rcv
1514	hidnplayr	1086
1534	hidnplayr	1087	DEBUGF 1,"TCP state = syn received\n"
1533	hidnplayr	1088
1719	hidnplayr	1089	;;;;; 801-815
1514	hidnplayr	1090
1719	hidnplayr	1091	.no_syn_rcv:
1514	hidnplayr	1092
1719	hidnplayr	1093	; check for duplicate ACK
1533	hidnplayr	1094
1719	hidnplayr	1095	mov eax, [edx + TCP_segment.AckNumber]
		1096	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
		1097	jg .not_dup_ack
1514	hidnplayr	1098
1719	hidnplayr	1099	DEBUGF 1,"Duplicate ACK\n"
1514	hidnplayr	1100
1719	hidnplayr	1101	test ecx, ecx
		1102	jnz .ack_processed
1514	hidnplayr	1103
1719	hidnplayr	1104	mov eax, dword [edx + TCP_segment.Window]
		1105	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		1106	jne .ack_processed
1533	hidnplayr	1107
1719	hidnplayr	1108	; Process the duplicate ACK
		1109
		1110	;;;;; 833 - 878
		1111
		1112	;;; call TCP_output
		1113	jmp .drop
		1114
		1115	.not_dup_ack:
		1116
		1117	DEBUGF 1,"new ACK\n"
		1118
		1119
1514	hidnplayr	1120	;-------------------------------------------------
1519	hidnplayr	1121	; If the congestion window was inflated to account
1719	hidnplayr	1122	; for the other side's cached packets, retract it
1514	hidnplayr	1123
		1124	;;;; 888 - 902
		1125
		1126
		1127	;------------------------------------------
		1128	; RTT measurements and retransmission timer
		1129
		1130	;;;;; 903 - 926
		1131
1519	hidnplayr	1132	mov [ebx + TCP_SOCKET.timer_retransmission], 0
1514	hidnplayr	1133
1519	hidnplayr	1134	mov eax, [ebx + TCP_SOCKET.SND_MAX]
		1135	cmp eax, [edx + TCP_segment.AckNumber]
		1136	je .all_outstanding
1543	hidnplayr	1137	mov [ebx + TCP_SOCKET.timer_retransmission], 120 ;;;; TODO: correct this value (use a macro for it)
1519	hidnplayr	1138	.all_outstanding:
		1139
1514	hidnplayr	1140	;-------------------------------------------
		1141	; Open congestion window in response to ACKs
		1142
		1143	;;;;
		1144
		1145
		1146	;------------------------------------------
		1147	; Remove acknowledged data from send buffer
		1148
1536	hidnplayr	1149	pusha
		1150	mov ecx, [edx + TCP_segment.AckNumber]
1719	hidnplayr	1151	sub ecx, [ebx + TCP_SOCKET.SND_UNA] ; ecx now holds number of bytes acked
		1152
1533	hidnplayr	1153	lea eax, [ebx + STREAM_SOCKET.snd]
1536	hidnplayr	1154	call SOCKET_ring_free
		1155	popa
1514	hidnplayr	1156
1719	hidnplayr	1157	;---------------------------------------
		1158	; Wake up process waiting on send buffer
1536	hidnplayr	1159
1719	hidnplayr	1160	mov eax, ebx
		1161	call SOCKET_notify_owner
1536	hidnplayr	1162
1719	hidnplayr	1163	; Update TCB
1542	hidnplayr	1164
1536	hidnplayr	1165	mov eax, [edx + TCP_segment.AckNumber]
		1166	mov [ebx + TCP_SOCKET.SND_UNA], eax
		1167
		1168	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		1169	jl @f
		1170	mov [ebx + TCP_SOCKET.SND_NXT], eax
		1171	@@:
		1172
1719	hidnplayr	1173	; General ACK handling complete
		1174	; Now do the state-specific ones
1536	hidnplayr	1175
1514	hidnplayr	1176	mov eax, [ebx + TCP_SOCKET.t_state]
1719	hidnplayr	1177	jmp dword [eax*4 + .ACK_sw_list]
1514	hidnplayr	1178
		1179	.ACK_sw_list:
1719	hidnplayr	1180	dd .ack_processed ;TCB_CLOSED
		1181	dd .ack_processed ;TCB_LISTEN
		1182	dd .ack_processed ;TCB_SYN_SENT
		1183	dd .ack_processed ;TCB_SYN_RECEIVED
		1184	dd .ack_processed ;TCB_ESTABLISHED
		1185	dd .ack_processed ;TCB_CLOSE_WAIT
		1186	dd .ack_fw1 ;TCB_FIN_WAIT_1
		1187	dd .ack_c ;TCB_CLOSING
		1188	dd .ack_la ;TCB_LAST_ACK
		1189	dd .ack_processed ;TCB_FIN_WAIT_2
		1190	dd .ack_tw ;TCB_TIMED_WAIT
1514	hidnplayr	1191
		1192
1719	hidnplayr	1193	.ack_fw1:
1514	hidnplayr	1194
1719	hidnplayr	1195	;;; TODO: 963
1514	hidnplayr	1196
1719	hidnplayr	1197	jmp .ack_processed
1514	hidnplayr	1198
1719	hidnplayr	1199	.ack_c:
1514	hidnplayr	1200
1719	hidnplayr	1201	;;; TODO: 958
1514	hidnplayr	1202
1719	hidnplayr	1203	jmp .ack_processed
1514	hidnplayr	1204
1719	hidnplayr	1205	.ack_la:
1514	hidnplayr	1206
1719	hidnplayr	1207	;;; TODO: 999
1514	hidnplayr	1208
1719	hidnplayr	1209	jmp .ack_processed
1514	hidnplayr	1210
		1211
1719	hidnplayr	1212	.ack_tw:
1514	hidnplayr	1213
1719	hidnplayr	1214	;;; TODO: 1010
1514	hidnplayr	1215
1719	hidnplayr	1216	jmp .ack_processed
1514	hidnplayr	1217
		1218
1719	hidnplayr	1219	.ack_processed:
		1220
		1221	DEBUGF 1,"ack processed\n"
		1222
1536	hidnplayr	1223	;----------------------------------------------
		1224	; check if we need to update window information
1514	hidnplayr	1225
		1226	test [edx + TCP_segment.Flags], TH_ACK
		1227	jz .no_window_update
		1228
		1229	mov eax, [ebx + TCP_SOCKET.SND_WL1]
		1230	cmp eax, [edx + TCP_segment.SequenceNumber]
1536	hidnplayr	1231	jl .update_window
		1232	jg @f
1514	hidnplayr	1233
		1234	mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1235	cmp eax, [edx + TCP_segment.AckNumber]
1536	hidnplayr	1236	jl .update_window
		1237	jg .no_window_update
		1238	@@:
1514	hidnplayr	1239
1543	hidnplayr	1240	mov eax, [ebx + TCP_SOCKET.SND_WL2]
1536	hidnplayr	1241	cmp eax, [edx + TCP_segment.AckNumber]
		1242	jne .no_window_update
		1243
		1244	movzx eax, [edx + TCP_segment.Window]
1514	hidnplayr	1245	cmp eax, [ebx + TCP_SOCKET.SND_WND]
1536	hidnplayr	1246	jle .no_window_update
1514	hidnplayr	1247
1536	hidnplayr	1248	.update_window:
1514	hidnplayr	1249
1536	hidnplayr	1250	DEBUGF 1,"Updating window\n"
1514	hidnplayr	1251
1536	hidnplayr	1252	;----------------------------------
		1253	; Keep track of pure window updates
		1254
		1255	; test ecx, ecx
		1256	; jz @f
		1257	;
		1258	; mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1259	; cmp eax, [edx + TCP_segment.AckNumber]
		1260	; jne @f
		1261	;
		1262	; ;; mov eax, tiwin
		1263	; cmp eax, [ebx + TCP_SOCKET.SND_WND]
		1264	; jle @f
		1265	;
		1266	; ;;; update stats
		1267	;
		1268	; @@:
		1269
1543	hidnplayr	1270	mov eax, dword [edx + TCP_segment.Window]
1514	hidnplayr	1271	cmp eax, [ebx + TCP_SOCKET.max_sndwnd]
		1272	jle @f
		1273	mov [ebx + TCP_SOCKET.max_sndwnd], eax
		1274	@@:
		1275	mov [ebx + TCP_SOCKET.SND_WND], eax
		1276
1536	hidnplayr	1277	push [edx + TCP_segment.SequenceNumber]
		1278	pop [ebx + TCP_SOCKET.SND_WL1]
1514	hidnplayr	1279
1536	hidnplayr	1280	push [edx + TCP_segment.AckNumber]
		1281	pop [ebx + TCP_SOCKET.SND_WL2]
1514	hidnplayr	1282
		1283	;;; needoutput = 1
		1284
		1285	.no_window_update:
		1286
		1287	;-----------------
		1288	; process URG flag
		1289
		1290	test [edx + TCP_segment.Flags], TH_URG
		1291	jz .not_urgent
		1292
		1293	cmp [edx + TCP_segment.UrgentPointer], 0
		1294	jz .not_urgent
		1295
		1296	cmp [ebx + TCP_SOCKET.t_state], TCB_TIMED_WAIT
		1297	je .not_urgent
		1298
		1299	; Ignore bogus urgent offsets
		1300
		1301	;;; 1040-1050
		1302
		1303	movzx eax, [edx + TCP_segment.UrgentPointer]
1533	hidnplayr	1304	add eax, [ebx + STREAM_SOCKET.rcv + RING_BUFFER.size]
1514	hidnplayr	1305	cmp eax, SOCKET_MAXDATA
		1306	jle .not_urgent
		1307
		1308	mov [edx + TCP_segment.UrgentPointer], 0
		1309	and [edx + TCP_segment.Flags], not (TH_URG)
		1310	jmp .do_data
		1311
		1312	.not_urgent:
		1313
		1314	;--------------------------------------
		1315	; processing of received urgent pointer
		1316
1529	hidnplayr	1317	;;; TODO (1051-1093)
1514	hidnplayr	1318
1529	hidnplayr	1319	;--------------------------------
		1320	; process the data in the segment
1514	hidnplayr	1321
1529	hidnplayr	1322	.do_data:
1514	hidnplayr	1323
1534	hidnplayr	1324	DEBUGF 1,"TCP: do data (%u)\n", ecx
1514	hidnplayr	1325
		1326	test [edx + TCP_segment.Flags], TH_FIN
1529	hidnplayr	1327	jnz .process_fin
1514	hidnplayr	1328
1533	hidnplayr	1329	cmp [ebx + TCP_SOCKET.t_state], TCB_FIN_WAIT_1
1514	hidnplayr	1330	jge .dont_do_data
		1331
1533	hidnplayr	1332	test ecx, ecx
		1333	jz .final_processing
		1334
1514	hidnplayr	1335	DEBUGF 1,"Processing data in segment\n"
		1336
1533	hidnplayr	1337	;; TODO: check if data is in sequence !
1514	hidnplayr	1338
1533	hidnplayr	1339	movzx eax, [edx + TCP_segment.DataOffset] ;;; todo: remember this in.. edi ?
		1340	and eax, 0xf0
		1341	shr al, 2
		1342
		1343	lea esi, [edx + eax]
		1344
		1345	or [ebx + TCP_SOCKET.t_flags], TF_DELACK
1543	hidnplayr	1346	add [ebx + TCP_SOCKET.RCV_NXT], ecx
1533	hidnplayr	1347
		1348	lea eax, [ebx + STREAM_SOCKET.rcv]
		1349	call SOCKET_ring_write
		1350
		1351	mov eax, ebx
		1352	call SOCKET_notify_owner
		1353
1514	hidnplayr	1354	jmp .final_processing
		1355
		1356
		1357	.dont_do_data:
		1358
		1359	;---------------
		1360	; FIN processing
		1361
		1362	.process_fin:
		1363
		1364	DEBUGF 1,"Processing FIN\n"
		1365
		1366	mov eax, [ebx + TCP_SOCKET.t_state]
		1367	shl eax, 2
		1368	jmp dword [eax + .FIN_sw_list]
		1369
		1370	.FIN_sw_list:
		1371	dd .no_fin ;TCB_CLOSED
		1372	dd .no_fin ;TCB_LISTEN
		1373	dd .no_fin ;TCB_SYN_SENT
1533	hidnplayr	1374	dd .fin_syn_est ;TCB_SYN_RECEIVED
		1375	dd .fin_syn_est ;TCB_ESTABLISHED
1514	hidnplayr	1376	dd .no_fin ;TCB_CLOSE_WAIT
1533	hidnplayr	1377	dd .fin_wait1 ;TCB_FIN_WAIT_1
1514	hidnplayr	1378	dd .no_fin ;TCB_CLOSING
		1379	dd .no_fin ;TCB_LAST_ACK
1533	hidnplayr	1380	dd .fin_wait2 ;TCB_FIN_WAIT_2
		1381	dd .fin_timed ;TCB_TIMED_WAIT
1514	hidnplayr	1382
		1383
		1384
1533	hidnplayr	1385	.fin_syn_est:
1514	hidnplayr	1386
1533	hidnplayr	1387	jmp .final_processing
1514	hidnplayr	1388
1533	hidnplayr	1389	.fin_wait1:
1514	hidnplayr	1390
1533	hidnplayr	1391	jmp .final_processing
1514	hidnplayr	1392
1533	hidnplayr	1393	.fin_wait2:
1514	hidnplayr	1394
1533	hidnplayr	1395	jmp .final_processing
		1396
		1397	.fin_timed:
		1398
		1399	jmp .final_processing
		1400
1514	hidnplayr	1401	.no_fin:
		1402
		1403	;-----------------
		1404	; Final processing
		1405
		1406	.final_processing:
		1407
		1408	DEBUGF 1,"Final processing\n"
		1409
1533	hidnplayr	1410	mov [ebx + SOCKET.lock], 0
		1411
1514	hidnplayr	1412	;;; if debug enabled, output packet
		1413
1719	hidnplayr	1414	;test needoutput, needoutput
		1415	;jz .dumpit
1514	hidnplayr	1416
		1417	test [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1719	hidnplayr	1418	jz .dumpit
1514	hidnplayr	1419
1529	hidnplayr	1420	DEBUGF 1,"ACK now!\n"
		1421
		1422	push ebx
		1423	mov eax, ebx
1514	hidnplayr	1424	call TCP_output
1529	hidnplayr	1425	pop ebx
1514	hidnplayr	1426
1719	hidnplayr	1427	.dumpit:
		1428
1274	hidnplayr	1429	call kernel_free
1529	hidnplayr	1430	add esp, 4
		1431	ret
1274	hidnplayr	1432
1514	hidnplayr	1433	;------------------------------------------
		1434	; Generate an ACK, droping incoming segment
1274	hidnplayr	1435
1514	hidnplayr	1436	align 4
		1437	.drop_after_ack:
1274	hidnplayr	1438
1514	hidnplayr	1439	DEBUGF 1,"Drop after ACK\n"
1274	hidnplayr	1440
1514	hidnplayr	1441	test [edx + TCP_segment.Flags], TH_RST
		1442	jnz .drop
1274	hidnplayr	1443
1514	hidnplayr	1444	and [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1274	hidnplayr	1445
1529	hidnplayr	1446	push ebx
		1447	mov eax, ebx
1514	hidnplayr	1448	call TCP_output
1529	hidnplayr	1449	pop ebx
1318	hidnplayr	1450
1514	hidnplayr	1451	call kernel_free
1529	hidnplayr	1452	add esp, 4
		1453	ret
1274	hidnplayr	1454
1514	hidnplayr	1455
		1456	;-------------------------------------------
		1457	; Generate an RST, dropping incoming segment
		1458
		1459	align 4
		1460	.drop_with_reset:
		1461
		1462	DEBUGF 1,"Drop with reset\n"
		1463
		1464	test [edx + TCP_segment.Flags], TH_RST
		1465	jnz .drop
		1466
		1467	;;; if its a multicast/broadcast, also drop
		1468
		1469	test [edx + TCP_segment.Flags], TH_ACK
		1470	jnz .respond_ack
		1471
		1472	test [edx + TCP_segment.Flags], TH_SYN
		1473	jnz .respond_syn
		1474
		1475	call kernel_free
1529	hidnplayr	1476	add esp, 4
		1477	ret
1514	hidnplayr	1478
		1479	.respond_ack:
		1480
1533	hidnplayr	1481	mov dl, TH_RST
1514	hidnplayr	1482
1533	hidnplayr	1483	push ebx
1529	hidnplayr	1484	call TCP_respond_segment
1533	hidnplayr	1485	pop ebx
1514	hidnplayr	1486
		1487	jmp .destroy_new_socket
		1488
		1489
		1490	.respond_syn:
		1491
1533	hidnplayr	1492	mov dl, TH_RST + TH_ACK
1514	hidnplayr	1493
1533	hidnplayr	1494	push ebx
		1495	call TCP_respond_socket
		1496	pop ebx
1514	hidnplayr	1497
		1498	jmp .destroy_new_socket
		1499
		1500	;-----
		1501	; Drop
		1502
		1503	align 4
		1504	.drop:
		1505
		1506	DEBUGF 1,"Dropping packet\n"
		1507
		1508	;;;; If debugging options are enabled, output the packet somwhere
		1509
		1510	.destroy_new_socket:
		1511
		1512	;;;; kill the newly created socket
		1513
		1514	call kernel_free
1529	hidnplayr	1515	add esp, 4
		1516	ret
1514	hidnplayr	1517
		1518
		1519
		1520
		1521
		1522
		1523	;---------------------------
		1524	;
		1525	; TCP_pull_out_of_band
		1526	;
		1527	; IN: eax =
		1528	; ebx = socket ptr
		1529	; edx = tcp packet ptr
		1530	;
		1531	; OUT: /
		1532	;
		1533	;---------------------------
		1534
		1535	align 4
		1536	TCP_pull_out_of_band:
		1537
		1538	DEBUGF 1,"TCP_pull_out_of_band\n"
		1539
		1540	;;;; 1282-1305
		1541
1318	hidnplayr	1542	ret
		1543
		1544
		1545
		1546	;-----------------------------------------------------------------
		1547	;
1514	hidnplayr	1548	; TCP_output
1318	hidnplayr	1549	;
1519	hidnplayr	1550	; IN: eax = socket pointer
1514	hidnplayr	1551	;
1318	hidnplayr	1552	; OUT: /
		1553	;
		1554	;-----------------------------------------------------------------
		1555	align 4
1514	hidnplayr	1556	TCP_output:
1318	hidnplayr	1557
1514	hidnplayr	1558	DEBUGF 1,"TCP_output, socket: %x\n", eax
1318	hidnplayr	1559
1514	hidnplayr	1560	; We'll detect the length of the data to be transmitted, and flags to be used
		1561	; If there is some data, or any critical controls to send (SYN / RST), then transmit
		1562	; Otherwise, investigate further
1318	hidnplayr	1563
1514	hidnplayr	1564	mov ebx, [eax + TCP_SOCKET.SND_MAX]
		1565	cmp ebx, [eax + TCP_SOCKET.SND_UNA]
		1566	jne .not_idle
1318	hidnplayr	1567
1514	hidnplayr	1568	mov ebx, [eax + TCP_SOCKET.t_idle]
		1569	cmp ebx, [eax + TCP_SOCKET.t_rxtcur]
		1570	jle .not_idle
1318	hidnplayr	1571
1514	hidnplayr	1572	; We have been idle for a while and no ACKS are expected to clock out any data we send..
		1573	; Slow start to get ack "clock" running again.
1318	hidnplayr	1574
1514	hidnplayr	1575	mov ebx, [eax + TCP_SOCKET.t_maxseg]
		1576	mov [eax + TCP_SOCKET.SND_CWND], ebx
1318	hidnplayr	1577
1514	hidnplayr	1578	.not_idle:
		1579	.again:
		1580	mov ebx, [eax + TCP_SOCKET.SND_NXT] ; calculate offset
		1581	sub ebx, [eax + TCP_SOCKET.SND_UNA] ;
1318	hidnplayr	1582
1514	hidnplayr	1583	mov ecx, [eax + TCP_SOCKET.SND_WND] ; determine window
		1584	cmp ecx, [eax + TCP_SOCKET.SND_CWND] ;
		1585	jl @f ;
		1586	mov ecx, [eax + TCP_SOCKET.SND_CWND] ;
		1587	@@: ;
1318	hidnplayr	1588
1529	hidnplayr	1589	call TCP_outflags ; in dl
1318	hidnplayr	1590
1514	hidnplayr	1591	; If in persist timeout with window of 0, send 1 byte.
		1592	; Otherwise, if window is small but nonzero, and timer expired,
		1593	; we will send what we can and go to transmit state
1318	hidnplayr	1594
1514	hidnplayr	1595	test [eax + TCP_SOCKET.t_force], -1
		1596	jz .no_persist_timeout
1318	hidnplayr	1597
1514	hidnplayr	1598	test ecx, ecx
		1599	jnz .no_zero_window
1255	hidnplayr	1600
1533	hidnplayr	1601	cmp ebx, [eax + STREAM_SOCKET.snd + RING_BUFFER.size]
1514	hidnplayr	1602	jge @f
1255	hidnplayr	1603
1514	hidnplayr	1604	and dl, not (TH_FIN) ; clear the FIN flag ??? how can it be set before?
1255	hidnplayr	1605
1514	hidnplayr	1606	@@:
		1607	inc ecx
		1608	jmp .no_persist_timeout
1255	hidnplayr	1609
1514	hidnplayr	1610	.no_zero_window:
1254	hidnplayr	1611
1543	hidnplayr	1612	mov [eax + TCP_SOCKET.timer_persist], 0
1514	hidnplayr	1613	mov [eax + TCP_SOCKET.t_rxtshift], 0
1254	hidnplayr	1614
1514	hidnplayr	1615	.no_persist_timeout:
1159	hidnplayr	1616
1514	hidnplayr	1617	;;;106
1159	hidnplayr	1618
1533	hidnplayr	1619	mov esi, [eax + STREAM_SOCKET.snd + RING_BUFFER.size]
1514	hidnplayr	1620	cmp esi, ecx
		1621	jl @f
		1622	mov esi, ecx
		1623	@@:
		1624	sub esi, ebx
1254	hidnplayr	1625
1514	hidnplayr	1626	cmp esi, -1
		1627	jne .not_minus_one
1159	hidnplayr	1628
1514	hidnplayr	1629	; If FIN has been set, but not ACKed, and we havent been called to retransmit,
		1630	; len (esi) will be -1
		1631	; Otherwise, window shrank after we sent into it.
		1632	; If window shrank to 0, cancel pending retransmit and pull SND_NXT back to (closed) window
		1633	; We will enter persist state below.
		1634	; If window didn't close completely, just wait for an ACK
1159	hidnplayr	1635
1514	hidnplayr	1636	xor esi, esi
1159	hidnplayr	1637
1514	hidnplayr	1638	test ecx, ecx
		1639	jnz @f
1159	hidnplayr	1640
1529	hidnplayr	1641	mov [eax + TCP_SOCKET.timer_retransmission], 0 ; cancel retransmit
1274	hidnplayr	1642
1514	hidnplayr	1643	push [eax + TCP_SOCKET.SND_UNA]
		1644	pop [eax + TCP_SOCKET.SND_NXT]
		1645	@@:
1254	hidnplayr	1646
1514	hidnplayr	1647	.not_minus_one:
1254	hidnplayr	1648
1514	hidnplayr	1649	;;; 124
1159	hidnplayr	1650
1514	hidnplayr	1651	cmp esi, [eax + TCP_SOCKET.t_maxseg]
		1652	jle @f
1274	hidnplayr	1653
1514	hidnplayr	1654	mov esi, [eax + TCP_SOCKET.t_maxseg]
		1655	;sendalot = 1
1274	hidnplayr	1656
1514	hidnplayr	1657	@@:
1274	hidnplayr	1658
1514	hidnplayr	1659	;;; 128
1274	hidnplayr	1660
1514	hidnplayr	1661	mov edi, [eax + TCP_SOCKET.SND_NXT]
		1662	add edi, esi ; len
		1663	sub edi, [eax + TCP_SOCKET.SND_UNA]
1533	hidnplayr	1664	add edi, [eax + STREAM_SOCKET.snd + RING_BUFFER.size]
1514	hidnplayr	1665	cmp edi, 0
		1666	jle @f
1274	hidnplayr	1667
1514	hidnplayr	1668	and dl, not (TH_FIN) ; clear the FIN flag
1159	hidnplayr	1669
1514	hidnplayr	1670	@@:
1159	hidnplayr	1671
		1672
1529	hidnplayr	1673	; set ecx to space available in receive buffer
		1674	; From now on, ecx will be the window we advertise to the other end
1159	hidnplayr	1675
1529	hidnplayr	1676	mov ecx, SOCKET_MAXDATA
1533	hidnplayr	1677	sub ecx, [eax + STREAM_SOCKET.rcv + RING_BUFFER.size]
1159	hidnplayr	1678
1514	hidnplayr	1679	;------------------------------
		1680	; Sender silly window avoidance
1159	hidnplayr	1681
1529	hidnplayr	1682	cmp ecx, [eax + TCP_SOCKET.t_maxseg]
1514	hidnplayr	1683	je .send
1274	hidnplayr	1684
1514	hidnplayr	1685	;;; TODO: 144-145
1274	hidnplayr	1686
1514	hidnplayr	1687	test [eax + TCP_SOCKET.t_force], -1
		1688	jnz .send
1274	hidnplayr	1689
1529	hidnplayr	1690	mov ebx, [eax + TCP_SOCKET.max_sndwnd]
		1691	shr ebx, 1
		1692	cmp ecx, ebx
		1693	jge .send
1274	hidnplayr	1694
1529	hidnplayr	1695	mov ebx, [eax + TCP_SOCKET.SND_NXT]
		1696	cmp ebx, [eax + TCP_SOCKET.SND_MAX]
		1697	jl .send
1254	hidnplayr	1698
1514	hidnplayr	1699	;----------------------------------------
		1700	; Check if a window update should be sent
1159	hidnplayr	1701
1529	hidnplayr	1702	test ecx, ecx ; window
		1703	jz .no_window
1159	hidnplayr	1704
1514	hidnplayr	1705	;;; TODO 154-172
1159	hidnplayr	1706
1514	hidnplayr	1707	.no_window:
1159	hidnplayr	1708
1514	hidnplayr	1709	;--------------------------
		1710	; Should a segment be sent?
1159	hidnplayr	1711
1534	hidnplayr	1712	test [eax + TCP_SOCKET.t_flags], TF_ACKNOW
1514	hidnplayr	1713	jnz .send
1159	hidnplayr	1714
1514	hidnplayr	1715	test dl, TH_SYN + TH_RST
		1716	jnz .send
1159	hidnplayr	1717
1534	hidnplayr	1718	mov ebx, [eax + TCP_SOCKET.SND_UP]
		1719	cmp ebx, [eax + TCP_SOCKET.SND_UNA]
1514	hidnplayr	1720	jg .send
1249	hidnplayr	1721
1514	hidnplayr	1722	test dl, TH_FIN
		1723	jz .enter_persist
1318	hidnplayr	1724
1534	hidnplayr	1725	test [eax + TCP_SOCKET.t_flags], TF_SENTFIN
1514	hidnplayr	1726	jnz .send
1254	hidnplayr	1727
1534	hidnplayr	1728	mov ebx, [eax + TCP_SOCKET.SND_NXT]
		1729	cmp ebx, [eax + TCP_SOCKET.SND_UNA]
1514	hidnplayr	1730	je .send
1254	hidnplayr	1731
1514	hidnplayr	1732	;--------------------
		1733	; Enter persist state
1318	hidnplayr	1734
1514	hidnplayr	1735	.enter_persist:
1318	hidnplayr	1736
1519	hidnplayr	1737	DEBUGF 1,"Entering persist state\n"
1318	hidnplayr	1738
1514	hidnplayr	1739	;--------------------------------------
		1740	; No reason to send a segment, just ret
1318	hidnplayr	1741
1514	hidnplayr	1742	DEBUGF 1,"No reason to send a segment\n"
1318	hidnplayr	1743
1514	hidnplayr	1744	ret
1318	hidnplayr	1745
		1746
1514	hidnplayr	1747	;-----------------------------------------------
		1748	;
		1749	; Send a segment
		1750	;
1529	hidnplayr	1751	; eax = socket pointer
1514	hidnplayr	1752	; dl = flags
		1753	;
		1754	;-----------------------------------------------
1318	hidnplayr	1755
1529	hidnplayr	1756	.send:
1318	hidnplayr	1757
1514	hidnplayr	1758	DEBUGF 1,"Preparing to send a segment\n"
1318	hidnplayr	1759
1529	hidnplayr	1760	mov edi, TCP_segment.Data ; edi will contain headersize
1318	hidnplayr	1761
1529	hidnplayr	1762	sub esp, 8 ; create some space on stack
		1763	push eax ; save this too..
		1764
1514	hidnplayr	1765	;------------------------------------
		1766	; Send options with first SYN segment
1318	hidnplayr	1767
1514	hidnplayr	1768	test dl, TH_SYN
		1769	jz .no_options
1318	hidnplayr	1770
1529	hidnplayr	1771	push [eax + TCP_SOCKET.ISS]
		1772	pop [eax + TCP_SOCKET.SND_NXT]
1318	hidnplayr	1773
1529	hidnplayr	1774	test [eax + TCP_SOCKET.t_flags], TF_NOOPT
1514	hidnplayr	1775	jnz .no_options
1318	hidnplayr	1776
1529	hidnplayr	1777	mov ecx, 1460
		1778	or ecx, TCP_OPT_MAXSEG shl 24 + 4 shl 16
		1779	bswap ecx
		1780	push ecx
		1781	add di, 4
1514	hidnplayr	1782
1529	hidnplayr	1783	test [eax + TCP_SOCKET.t_flags], TF_REQ_SCALE
1514	hidnplayr	1784	jz .no_syn
		1785
		1786	test dl, TH_ACK
		1787	jnz .scale_opt
		1788
1529	hidnplayr	1789	test [eax + TCP_SOCKET.t_flags], TF_RCVD_SCALE
1514	hidnplayr	1790	jz .no_syn
		1791
		1792	.scale_opt:
1529	hidnplayr	1793	movzx ecx, byte [eax + TCP_SOCKET.request_r_scale]
		1794	or ecx, TCP_OPT_WINDOW shl 24 + 4 shl 16 + TCP_OPT_NOP shl 8
		1795	bswap ecx
		1796	pushd ecx
1514	hidnplayr	1797	add di, 4
1159	hidnplayr	1798
1514	hidnplayr	1799	.no_syn:
1159	hidnplayr	1800
1514	hidnplayr	1801	;------------------------------------
		1802	; Make the timestamp option if needed
1159	hidnplayr	1803
1529	hidnplayr	1804	test [eax + TCP_SOCKET.t_flags], TF_REQ_TSTMP
1514	hidnplayr	1805	jz .no_timestamp
1159	hidnplayr	1806
1514	hidnplayr	1807	test dl, TH_RST
		1808	jnz .no_timestamp
		1809
		1810	test dl, TH_ACK
		1811	jz .timestamp
		1812
1529	hidnplayr	1813	test [eax + TCP_SOCKET.t_flags], TF_RCVD_TSTMP
1514	hidnplayr	1814	jz .no_timestamp
		1815
		1816	.timestamp:
1529	hidnplayr	1817	mov esi, [timer_ticks]
		1818	bswap esi
		1819	push esi
1514	hidnplayr	1820	pushw 0
1529	hidnplayr	1821	pushd TCP_OPT_TIMESTAMP + 10 shl 8 + TCP_OPT_NOP shl 16 + TCP_OPT_NOP shl 24
1514	hidnplayr	1822	add di, 10
		1823
		1824	.no_timestamp:
		1825	;; TODO: check if we dont exceed the max segment size
		1826
		1827	.no_options:
1529	hidnplayr	1828	; eax = socket ptr
		1829	; edx = flags
		1830	; ecx = data size
		1831	; edi = header size
		1832	; esi = snd ring buff ptr
1514	hidnplayr	1833
1533	hidnplayr	1834	mov ecx, [eax + STREAM_SOCKET.snd + RING_BUFFER.size]
		1835	cmp ecx, [eax + TCP_SOCKET.t_maxseg] ;;; right?
		1836	jle @f
		1837	mov ecx, [eax + TCP_SOCKET.t_maxseg]
		1838	@@:
1514	hidnplayr	1839	add ecx, edi ; total TCP segment size
		1840
1529	hidnplayr	1841	; Start by pushing all TCP header values in reverse order on stack
		1842	; (essentially, creating the tcp header!)
1514	hidnplayr	1843
1529	hidnplayr	1844	pushw 0 ; .UrgentPointer dw ?
		1845	pushw 0 ; .Checksum dw ?
		1846	pushw 0x00a0 ; .Window dw ? ;;;;;;;
		1847	shl edi, 2 ; .DataOffset db ? only 4 left-most bits
		1848	shl dx, 8
		1849	or dx, di ; .Flags db ?
		1850	pushw dx
		1851	shr edi, 2 ; .DataOffset db ? ;;;;
1514	hidnplayr	1852
1529	hidnplayr	1853	push [eax + TCP_SOCKET.RCV_NXT] ; .AckNumber dd ?
1543	hidnplayr	1854	ntohd [esp]
1159	hidnplayr	1855
1529	hidnplayr	1856	push [eax + TCP_SOCKET.SND_NXT] ; .SequenceNumber dd ?
1543	hidnplayr	1857	ntohd [esp]
1159	hidnplayr	1858
1529	hidnplayr	1859	push [eax + TCP_SOCKET.RemotePort] ; .DestinationPort dw ?
1543	hidnplayr	1860	ntohw [esp]
1249	hidnplayr	1861
1529	hidnplayr	1862	push [eax + TCP_SOCKET.LocalPort] ; .SourcePort dw ?
1543	hidnplayr	1863	ntohw [esp]
1274	hidnplayr	1864
1533	hidnplayr	1865	push edi ; header size
1274	hidnplayr	1866
1529	hidnplayr	1867	; Create the IP packet
		1868	mov ebx, [eax + IP_SOCKET.LocalIP] ; source ip
		1869	mov eax, [eax + IP_SOCKET.RemoteIP] ; dest ip
		1870	mov di, IP_PROTO_TCP shl 8 + 128
		1871	call IPv4_output
		1872	jz .fail
1274	hidnplayr	1873
1529	hidnplayr	1874	;-----------------------------------------
		1875	; Move TCP header from stack to TCP packet
1274	hidnplayr	1876
1533	hidnplayr	1877	push ecx
		1878	mov ecx, [esp+4]
		1879	lea esi, [esp+4+4]
1529	hidnplayr	1880	shr ecx, 2
		1881	rep movsd
1533	hidnplayr	1882	pop ecx ; full TCP packet size
1274	hidnplayr	1883
1533	hidnplayr	1884	pop esi ; headersize
		1885	add esp, esi
1254	hidnplayr	1886
1533	hidnplayr	1887	mov [esp + 4], eax ; packet ptr
1530	hidnplayr	1888	mov [esp + 4+4], edx ; packet size
1254	hidnplayr	1889
1533	hidnplayr	1890	mov edx, edi ; begin of data
		1891	sub edx, esi ; begin of packet (edi = begin of data)
		1892	push ecx
		1893	sub ecx, esi ; data size
1159	hidnplayr	1894
1514	hidnplayr	1895	;--------------
		1896	; Copy the data
1159	hidnplayr	1897
1529	hidnplayr	1898	; eax = ptr to ring struct
		1899	; ecx = buffer size
		1900	; edi = ptr to buffer
1249	hidnplayr	1901
1536	hidnplayr	1902	; test ecx, ecx
1533	hidnplayr	1903	mov eax, [esp+4] ; socket ptr
1536	hidnplayr	1904	add [eax + TCP_SOCKET.SND_NXT], ecx
		1905	add eax, STREAM_SOCKET.snd
1533	hidnplayr	1906	push edx
1529	hidnplayr	1907	call SOCKET_ring_read
1536	hidnplayr	1908	pop esi
		1909	pop ecx
1529	hidnplayr	1910	pop eax
1254	hidnplayr	1911
1533	hidnplayr	1912	test [esi + TCP_segment.Flags], TH_SYN + TH_FIN
		1913	jz @f
		1914	inc [eax + TCP_SOCKET.SND_NXT]
		1915	;;; TODO: update sentfin flag
		1916	@@:
1254	hidnplayr	1917
1533	hidnplayr	1918	mov edx, [eax + TCP_SOCKET.SND_NXT]
		1919	cmp edx, [eax + TCP_SOCKET.SND_MAX]
		1920	jle @f
		1921	mov [eax + TCP_SOCKET.SND_MAX], edx
		1922
		1923	;;;; TODO: time transmission (420)
		1924	@@:
		1925
		1926	;;; TODO: set retransmission timer
		1927
		1928	;--------------------
		1929	; Create the checksum
		1930
1529	hidnplayr	1931	DEBUGF 1,"checksum: ptr=%x size=%u\n", esi, ecx
1159	hidnplayr	1932
1529	hidnplayr	1933	TCP_checksum (eax + IP_SOCKET.LocalIP), (eax + IP_SOCKET.RemoteIP)
		1934	mov [esi+TCP_segment.Checksum], dx
		1935
1514	hidnplayr	1936	;----------------
		1937	; Send the packet
1159	hidnplayr	1938
1529	hidnplayr	1939	DEBUGF 1,"Sending TCP Packet to device %x\n", ebx
		1940	call [ebx + NET_DEVICE.transmit]
		1941	ret
1159	hidnplayr	1942
1514	hidnplayr	1943
1529	hidnplayr	1944	.fail:
		1945	pop ecx
		1946	add esp, ecx
1536	hidnplayr	1947	add esp, 4+8
1529	hidnplayr	1948	DEBUGF 1,"TCP_output: failed\n"
1159	hidnplayr	1949	ret
		1950
1529	hidnplayr	1951
		1952
1514	hidnplayr	1953	;-------------------------
		1954	;
		1955	; TCP_outflags
		1956	;
		1957	; IN: eax = socket ptr
		1958	;
		1959	; OUT: edx = flags
		1960	;
		1961	;-------------------------
1249	hidnplayr	1962	align 4
1514	hidnplayr	1963	TCP_outflags:
1254	hidnplayr	1964
1514	hidnplayr	1965	mov edx, [eax + TCP_SOCKET.t_state]
		1966	movzx edx, byte [edx + .flaglist]
1254	hidnplayr	1967
1514	hidnplayr	1968	DEBUGF 1,"TCP_outflags, socket: %x, flags: %x\n", eax, dl
		1969
1159	hidnplayr	1970	ret
		1971
1514	hidnplayr	1972	.flaglist:
1159	hidnplayr	1973
1514	hidnplayr	1974	db TH_RST + TH_ACK ; TCB_CLOSED
		1975	db 0 ; TCB_LISTEN
		1976	db TH_SYN ; TCB_SYN_SENT
		1977	db TH_SYN + TH_ACK ; TCB_SYN_RECEIVED
		1978	db TH_ACK ; TCB_ESTABLISHED
		1979	db TH_ACK ; TCB_CLOSE_WAIT
		1980	db TH_SYN + TH_ACK ; TCB_FIN_WAIT_1
		1981	db TH_SYN + TH_ACK ; TCB_CLOSING
		1982	db TH_SYN + TH_ACK ; TCB_LAST_ACK
		1983	db TH_ACK ; TCB_FIN_WAIT_2
		1984	db TH_ACK ; TCB_TIMED_WAIT
1249	hidnplayr	1985
1514	hidnplayr	1986
1529	hidnplayr	1987
		1988
1514	hidnplayr	1989	;-------------------------
		1990	;
		1991	; TCP_drop
		1992	;
		1993	; IN: eax = socket ptr
1716	hidnplayr	1994	; ebx = error number
1514	hidnplayr	1995	;
1716	hidnplayr	1996	; OUT: eax = socket ptr
1514	hidnplayr	1997	;
		1998	;-------------------------
1249	hidnplayr	1999	align 4
1514	hidnplayr	2000	TCP_drop:
1254	hidnplayr	2001
1514	hidnplayr	2002	DEBUGF 1,"TCP_drop\n"
1254	hidnplayr	2003
1716	hidnplayr	2004	cmp [eax + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		2005	jl .no_syn_received
1159	hidnplayr	2006
1514	hidnplayr	2007	mov [eax + TCP_SOCKET.t_state], TCB_CLOSED
1159	hidnplayr	2008
1514	hidnplayr	2009	call TCP_output
1254	hidnplayr	2010
1716	hidnplayr	2011	;;; TODO: update stats
1514	hidnplayr	2012
1716	hidnplayr	2013	jmp TCP_close
		2014
		2015	.no_syn_received:
		2016
		2017	;;; TODO: update stats
		2018
		2019	;;; TODO: check if error code is "Connection timed out' and handle accordingly
		2020
		2021	mov [eax + SOCKET.errorcode], ebx
		2022
		2023	jmp TCP_close
		2024
		2025
		2026	;-------------------------
		2027	;
		2028	; TCP_close
		2029	;
		2030	; IN: eax = socket ptr
		2031	; OUT: eax = socket ptr
		2032	;
		2033	;-------------------------
		2034	align 4
		2035	TCP_close:
		2036
1719	hidnplayr	2037	DEBUGF 1,"TCP_close\n"
		2038
1716	hidnplayr	2039	;;; TODO: update RTT and mean deviation
		2040	;;; TODO: update slow start threshold
		2041	;;; TODO: release connection resources
		2042
1719	hidnplayr	2043	; Now, mark the socket as being disconnected
		2044
		2045	mov [eax + SOCKET.state], 0 ;;; FIXME
		2046
1159	hidnplayr	2047	ret
		2048
		2049
1254	hidnplayr	2050
		2051
1514	hidnplayr	2052	;---------------------------------------
		2053	;
1519	hidnplayr	2054	; The easy way to send an ACK/RST/keepalive segment
1514	hidnplayr	2055	;
1529	hidnplayr	2056	; TCP_respond_socket:
		2057	;
		2058	; IN: ebx = socket ptr
1519	hidnplayr	2059	; cl = flags
1514	hidnplayr	2060	;
1529	hidnplayr	2061	;--------------------------------------
1514	hidnplayr	2062	align 4
1529	hidnplayr	2063	TCP_respond_socket:
1254	hidnplayr	2064
1529	hidnplayr	2065	DEBUGF 1,"TCP_respond_socket\n"
1159	hidnplayr	2066
1519	hidnplayr	2067	;---------------------
		2068	; Create the IP packet
		2069
1529	hidnplayr	2070	push cx ebx
		2071	mov eax, [ebx + IP_SOCKET.RemoteIP]
		2072	mov ebx, [ebx + IP_SOCKET.LocalIP]
1519	hidnplayr	2073	mov ecx, TCP_segment.Data
1529	hidnplayr	2074	mov di , IP_PROTO_TCP shl 8 + 128
		2075	call IPv4_output
1519	hidnplayr	2076	test edi, edi
		2077	jz .error
1529	hidnplayr	2078	pop esi cx
		2079	push edx eax
1519	hidnplayr	2080
1529	hidnplayr	2081	;-----------------------------------------------
		2082	; Fill in the TCP header by using the socket ptr
1519	hidnplayr	2083
1529	hidnplayr	2084	mov ax, [esi + TCP_SOCKET.LocalPort]
		2085	rol ax, 8
		2086	stosw
		2087	mov ax, [esi + TCP_SOCKET.RemotePort]
		2088	rol ax, 8
		2089	stosw
		2090	mov eax, [esi + TCP_SOCKET.SND_NXT]
		2091	bswap eax
		2092	stosd
		2093	mov eax, [esi + TCP_SOCKET.RCV_NXT]
		2094	bswap eax
		2095	stosd
		2096	mov al, 0x50 ; Dataoffset: 20 bytes
		2097	stosb
		2098	mov al, cl
		2099	stosb
		2100	mov ax, [esi + TCP_SOCKET.RCV_WND]
		2101	rol ax, 8
		2102	stosw ; window
		2103	xor eax, eax
		2104	stosd ; checksum + urgentpointer
1519	hidnplayr	2105
		2106	;---------------------
		2107	; Fill in the checksum
		2108
		2109	.checksum:
1529	hidnplayr	2110	sub edi, TCP_segment.Data
		2111	mov ecx, TCP_segment.Data
		2112	xchg esi, edi
		2113	TCP_checksum (edi + IP_SOCKET.LocalIP), (esi + IP_SOCKET.RemoteIP)
		2114	mov [esi+TCP_segment.Checksum], dx
1519	hidnplayr	2115
		2116	;--------------------
		2117	; And send the segment
		2118
		2119	call [ebx + NET_DEVICE.transmit]
1159	hidnplayr	2120	ret
		2121
1519	hidnplayr	2122	.error:
1529	hidnplayr	2123	DEBUGF 1,"TCP_respond failed\n"
		2124	add esp, 2+4
1159	hidnplayr	2125
1519	hidnplayr	2126	ret
1514	hidnplayr	2127
1529	hidnplayr	2128
		2129
		2130	;-------------------------
		2131	; TCP_respond.segment:
		2132	;
		2133	; IN: edx = segment ptr (a previously received segment)
		2134	; cl = flags
		2135
		2136	align 4
		2137	TCP_respond_segment:
		2138
		2139	DEBUGF 1,"TCP_respond_segment\n"
		2140
		2141	;---------------------
		2142	; Create the IP packet
		2143
		2144	push cx edx
		2145	mov ebx, [edx - 20 + IPv4_Packet.SourceAddress] ;;;; and what if ip packet had options?!
		2146	mov eax, [edx - 20 + IPv4_Packet.DestinationAddress] ;;;
		2147	mov ecx, TCP_segment.Data
		2148	mov di , IP_PROTO_TCP shl 8 + 128
		2149	call IPv4_output
		2150	jz .error
1533	hidnplayr	2151	pop esi cx
1529	hidnplayr	2152
		2153	push edx eax
		2154
1519	hidnplayr	2155	;---------------------------------------------------
		2156	; Fill in the TCP header by using a received segment
		2157
		2158	mov ax, [esi + TCP_segment.DestinationPort]
		2159	rol ax, 8
		2160	stosw
		2161	mov ax, [esi + TCP_segment.SourcePort]
		2162	rol ax, 8
		2163	stosw
		2164	mov eax, [esi + TCP_segment.AckNumber]
		2165	bswap eax
		2166	stosd
		2167	xor eax, eax
		2168	stosd
		2169	mov al, 0x50 ; Dataoffset: 20 bytes
		2170	stosb
		2171	mov al, cl
		2172	stosb
		2173	mov ax, 1280
		2174	rol ax, 8
		2175	stosw ; window
		2176	xor eax, eax
		2177	stosd ; checksum + urgentpointer
		2178
1529	hidnplayr	2179	;---------------------
		2180	; Fill in the checksum
1519	hidnplayr	2181
1529	hidnplayr	2182	.checksum:
		2183	lea esi, [edi - TCP_segment.Data]
		2184	mov ecx, TCP_segment.Data
		2185	TCP_checksum (esi - 20 + IPv4_Packet.DestinationAddress), (esi - 20 + IPv4_Packet.DestinationAddress)
		2186	mov [esi+TCP_segment.Checksum], dx
1519	hidnplayr	2187
1529	hidnplayr	2188	;--------------------
		2189	; And send the segment
1519	hidnplayr	2190
1529	hidnplayr	2191	call [ebx + NET_DEVICE.transmit]
		2192	ret
1519	hidnplayr	2193
1529	hidnplayr	2194	.error:
		2195	DEBUGF 1,"TCP_respond failed\n"
		2196	add esp, 2+4
1519	hidnplayr	2197
		2198	ret
		2199
		2200
		2201
1254	hidnplayr	2202
		2203	;---------------------------------------------------------------------------
		2204	;
		2205	; TCP_API
		2206	;
		2207	; This function is called by system function 75
		2208	;
		2209	; IN: subfunction number in bl
		2210	; device number in bh
		2211	; ecx, edx, .. depends on subfunction
		2212	;
		2213	; OUT:
		2214	;
		2215	;---------------------------------------------------------------------------
		2216	align 4
		2217	TCP_API:
		2218
		2219	movzx eax, bh
		2220	shl eax, 2
		2221
		2222	test bl, bl
		2223	jz .packets_tx ; 0
		2224	dec bl
		2225	jz .packets_rx ; 1
		2226
		2227	.error:
		2228	mov eax, -1
		2229	ret
		2230
		2231	.packets_tx:
1514	hidnplayr	2232	add eax, TCP_segments_tx
1254	hidnplayr	2233	mov eax, [eax]
		2234	ret
		2235
		2236	.packets_rx:
1514	hidnplayr	2237	add eax, TCP_segments_rx
1254	hidnplayr	2238	mov eax, [eax]
		2239	ret

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(root)/kernel/branches/net/network/tcp.inc – Rev 1719